Car wont start, fuel problem

[SVT356393]

Hey guys,

She start and drove fine to work today. But when I went to go pick up some lunch she had a rough idle then died out. Tried to start it again while pressing the throttle thinking it was just flooded and wouldn't start.

Air and spark are there. I went and checked the kill switch in the truck, kill switch wasn't popped. Then broke out the tuner to get some codes, here's what I've got.

P1237 and P0148

Mods are
-BBK Throttle Body
-SCT custom tune
-Mafia Mass Airflow
-60lb Injectors
-Twin 340lph Fuel pumps
-2.76 Upper
-4lb lower
-CAI
-Flows

and recently installed Mac Prochambers, haven't retuned it due to my local tuner won't have the SCT programming till later this month/early June. Also it's currently on a 93 tune, sadly all I have to work with here is 91 and octane booster. :bored:

 

[2003_svtcobra]

hit your kill switch in the truck a few times. it could be popped and it just dont show it. also check your frps

 

[SVT356393]

hit your kill switch in the truck a few times. it could be popped and it just dont show it. also check your frps

The switch is stuck, when I press it nothing happens. The FRPS is good and clean, I used Electronics cleaner a few weeks ago on most of the plugs.

 

[SVT356393]

reset it a few times, and still no go

 

[2003_svtcobra]

unplug the frps see if it will start

 

[hotcobra03]

have u checked fuses,,

im on cell,1237 is that fpdm off line

car have pprv deleted? hose in tank is common to pop off

 

[SVT356393]

unplug the frps see if it will start

No go on the FRPS

have u checked fuses,,

im on cell,1237 is that fpdm off line

car have pprv deleted? hose in tank is common to pop off

That's correct I believe, I chased the wiring all the way back and it seems to have a problem at the FPDM. I have the FPDM out in hand right now, is the best place to replace it at the dealership? I tried Lethal and AM, they only had wiring harness.

And I didn't do a PPRV delete. How difficult is that hose to get to because that sounds like a probable cause. How to check, hotcobra03?

 

[hotcobra03]

No go on the FRPS



That's correct I believe, I chased the wiring all the way back and it seems to have a problem at the FPDM. I have the FPDM out in hand right now, is the best place to replace it at the dealership? I tried Lethal and AM, they only had wiring harness.

And I didn't do a PPRV delete. How difficult is that hose to get to because that sounds like a probable cause. How to check, hotcobra03?

do a search on pprv..i never did 1 to say..just it comes up alot..

not sure if po1237 will no start..po148 will

P1237 - Fuel Pump Secondary Circuit Malfunction Note: For LS6/LS8 and Thunderbird, the FPDM functions are incorporated in the rear electronics module (REM). Also, the REM does not use a FPM circuit. Diagnostic information will be set through SCP.
P1237 indicates that the FPDM has detected a fuel pump secondary circuit fault. The FPDM will send a message to the PCM through the FPM circuit, indicating that this failure has been detected. The PCM will set the DTC when the message is received.

• Open or shorted FP PWR circuit
• Open FP RTN circuit to FPDM
• Open or shorted circuit in the fuel pump
• Locked fuel pump rotor
• Damaged FPDM
• For LS6/LS8 and Thunderbird, circuits associated with the Fuel Pump relay

• The FPDM sends a 75% duty cycle (750 msec ON, 250 msec OFF) through the FPM circuit to the PCM while the fault is being detected by the FPDM. If the fault is no longer detected, the PCM will return to sending an "all OK" (50% duty cycle) message to the PCM. The PCM will keep P1237 stored in Continuous Memory.
• The FPDM controls pump speed by supplying a "variable" ground on the RTN circuit.

P0148 - Fuel Delivery Error At least one bank lean at wide open throttle.

• Severely restricted fuel filter.
• Severely restricted fuel supply line.

P1237 All GO to KB47
2003 PCED OBD
SECTION 5: Pinpoint Tests

Procedure revision date: 07/01/2003
KB: Fuel Pump Driver Module (FPDM)

KB: Introduction KB1 DTC P1233 OR P1234: IS DTC P1233 OR P1234 PRESENT IN KEY ON ENGINE OFF SELF TEST

Is DTC P1233 or P1234 present in Key On Engine Off Self-Test?
Yes No A hard fault is present. GO to KB2 . The PCM is now receiving a signal from the FPDM. One possible cause of the DTC P1233 or P1234 is that the IFS switch was tripped, then reset.

If engine is now a no start:

Disregard the DTC P1233 or P1234 at this time. RETURN to Section 3 and CONTINUE as directed. After servicing the no start, to diagnose intermittent causes of the DTC P1233 or P1234, RETURN to GO to KB25 .

If engine will start:

GO to KB25 to diagnose intermittent condition. KB2 DOES THE ENGINE START?

Does the engine start?
Yes No GO to KB15 (to check the FPM circuit). VERIFY IFS switch is set (button depressed). If OK, GO to KB3 . KB3 CHECK POWER AND GROUND CIRCUITS TO FPDM

• Disconnect FPDM.
• Key on, engine off.
• Measure voltage between the FPDM PWR pin and ground pin at the FPDM harness connector.

Is voltage greater than 10.5 volts?

Yes No Key off. REPLACE FPDM. GO to KB4 . KB4 CHECK POWER TO FPDM

• Key on, engine off.
• Measure voltage between the FPDM PWR pin at the FPDM harness connector and chassis ground.

Is voltage greater than 10.5 volts?

Yes No REPAIR open ground circuit to FPDM. KEY OFF. No power to FPDM.

For Escort, Mustang:

GO to KB5 .

All Others:

GO to KB8 . KB5 CHECK B+ VOLTAGE TO CCRM PIN 11 (FPDM POWER SUPPLY RELAY)

• Disconnect CCRM.
• Measure B+ circuit voltage at Pin 11 of the CCRM harness connector.

Is voltage greater than 10.5 volts?
Yes No For Mustang:

GO to KB6 .

For Escort:

GO to KB7 . VERIFY integrity of related fuse. If OK, REPAIR open B+ circuit. If fuse is damaged, CHECK B+ and FPDM PWR circuits for short to ground before replacing. KB6 CHECK GROUND CIRCUIT TO CCRM PIN 18

• Measure resistance of ground circuit between CCRM harness connector Pin 18 and chassis ground.

Is resistance less than 5.0 ohms?
Yes No GO to KB7 . SERVICE open ground circuit. KB7 CHECK FOR OPEN FPDM PWR CIRCUIT

• Measure resistance of FPDM PWR circuit between CCRM harness connector (pin 5) and FPDM harness connector.

Is resistance less than 5.0 ohms?
Yes No REPLACE CCRM. The FPDM PWR circuit is open. GO to KB13 to help isolate fault. KB8 CHECK B+ VOLTAGE TO FPDM POWER SUPPLY RELAY

• Disconnect FPDM power supply relay.
• Measure B+ circuit voltage at the FPDM power supply relay harness connector.

Is voltage greater than 10.5 volts?
Yes No GO to KB9 . VERIFY integrity of related fuse. If OK, REPAIR open B+ circuit. If fuse is damaged, CHECK B+ and FPDM PWR circuits for short to ground before replacing. KB9 CHECK FOR GROUND TO FPDM POWER SUPPLY RELAY

• Disconnect scan tool from DLC.
• Measure resistance of ground circuit between FPDM power supply relay harness connector and battery negative post.

Is resistance less than 5.0 ohms?
Yes No GO to KB10 . REPAIR open circuit. KB10 CHECK FOR OPEN FPDM PWR CIRCUIT

• Measure resistance of FPDM PWR circuit between FPDM power supply relay harness connector and FPDM harness connector.

Is resistance less than 5.0 ohms?
Yes No RECONNECT FPDM. GO to KB11 . The FPDM PWR circuit is open. GO to KB13 to help isolate fault. KB11 CHECK VPWR CIRCUIT VOLTAGE (IGN START/RUN for Taurus/Sable) TO FPDM POWER SUPPLY RELAY

• Key on, engine off.
• Measure VPWR circuit voltage (IGN START/RUN for Taurus/Sable) at the FPDM power supply relay harness connector.

Is voltage greater than 10.5 volts?
Yes No REPLACE FPDM power supply relay. REPAIR open VPWR (or IGN START/RUN) circuit. KB13 ISOLATE OPEN IN FPDM PWR CIRCUIT

• Disconnect IFS switch.
• Measure resistance of FPDM PWR circuit between IFS switch harness connector and FPDM power supply relay harness connector (for Escort and Mustang, CCRM harness connector [pin 5]).
• Measure resistance of FPDM PWR circuit between FPDM harness connector and IFS switch harness connector.

Are both resistances less than 5.0 ohms?
Yes No VERIFY that the IFS switch is set (button depressed). If OK, REPLACE IFS switch. REPAIR open in appropriate area of FPDM PWR circuit. KB15 CHECK FOR OPEN FPM CIRCUIT

• Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.
• Disconnect FPDM.
• Disconnect PCM.
• Measure resistance of FPM circuit between PCM harness connector and the FPDM harness connector.

Is resistance less than 5.0 ohms?
Yes No GO to KB16 . REPAIR open circuit. KB16 CHECK FPM CIRCUIT FOR SHORT TO POWER IN HARNESS

• Key on, engine off.
• Measure voltage between FPM circuit at the PCM harness connector and ground.

Is voltage less than 1.0 volt?
Yes No KEY OFF. GO to KB17 . REPAIR short circuit. KB17 CHECK FPM CIRCUIT FOR SHORT TO GROUND IN HARNESS

• Disconnect scan tool from DLC.
• Measure resistance between FPM circuit at the PCM harness connector and ground.

Is resistance greater than 10,000 ohms?
Yes No GO to KB18 . REPAIR short circuit. KB18 CHECK FOR FPM OUTPUT FROM FPDM

• Reconnect FPDM.
• Key on, engine off.
• Measure dc voltage between FPM circuit at the PCM harness connector and ground.

Is voltage between 0.02 and 1.0 volt dc? (It is OK for the voltage to cycle below this range and then return to within range.)
Yes No REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPLACE FPDM. KB25 CHECK CIRCUITS THAT MAY CAUSE AN INTERMITTENT LOSS OF POWER SUPPLY TO THE FPDM. ALSO CHECK FOR INTERMITTENT OPENS OR SHORTS ON THE FPM CIRCUIT.

• Note: Be aware that P1233/1234 could be set if the inertia fuel shutoff (IFS) switch was tripped then reset.
• Key on, engine off.
• Access FPM PID. Note: With no fault detected, the FPDM will send a 50% duty cycle signal (all OK) to the PCM on the FPM circuit. Depending on scan tools, the FPM PID may display 50%, or a random value that is fluctuating between 85 and 115%.
• Observe FPM PID for an indication of a fault while completing the following (look for the FPM PID to change from the 50% value, or to stop fluctuating):
  • Shake, wiggle, bend the following circuits:
    • FPDM ground.
    • FPDM PWR circuit to FPDM.
    • For Escort and Mustang, the B+ circuit to CCRM pin 11. For Mustang, also the ground circuit to CCRM Pin 18.
    • For all except Escort and Mustang, the B+ and ground circuits to FPDM power supply relay.
    • FPM circuit between the FPDM and the PCM.
  • Lightly tap on the IFS Switch, FPDM and CCRM or FPDM power supply relay to simulate road shock.
• Key off.

Is a fault indicated?
Yes No ISOLATE fault and REPAIR as necessary. Unable to duplicate or identify fault at this time. GO to Z1 . KB30 DTC P1235 OR P1236: IS DTC P1235 OR P1236 PRESENT IN KEY ON ENGINE OFF OR ENGINE RUNNING SELF TEST?

• Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.
  Note: For LS6/LS8 and Thunderbird, check if Electronic Throttle Control (ETC) DTC P2105 is present. An ETC system concern could cause a P1235/P1236, and should be diagnosed first.

Is DTC P1235 or P1236 present in Key On Engine Off or Engine Running Self-Test?
Yes No A hard fault is present. GO to KB31 to check the FP circuit. DTC P1235 or P1236 is intermittent.

For LS6/LS8 and Thunderbird :

GO to KB42 .

All others :

GO to KB45 . KB31 CHECK FOR OPEN FP CIRCUIT BETWEEN PCM AND FPDM

• Note: For LS6/LS8 and Thunderbird, the FPDM functions are incorporated in the Rear Electronics Module (REM). In the following steps, if directed to perform an action with the FPDM, complete the action with the REM. Refer to the pin numbers in the beginning of this pinpoint test.
• Disconnect FPDM.
• Disconnect PCM.
• Measure resistance of FP circuit between PCM harness connector pin and the FPDM harness connector.

Is resistance less than 5.0 ohms?
Yes No GO to KB32 . REPAIR open circuit. KB32 CHECK FP CIRCUIT FOR SHORT TO POWER IN HARNESS

• Key on, engine off.
• Measure voltage between FP circuit at PCM harness connector pin and ground.

Is voltage less than 1.0 volt?
Yes No KEY OFF. GO to KB33 . REPAIR short circuit. KB33 CHECK FP CIRCUIT FOR SHORT TO GROUND IN HARNESS

• Disconnect scan tool from DLC.
• Measure resistance between FP circuit at PCM harness connector pin and ground.

Is resistance greater than 10,000 ohms?
Yes No For LS6/LS8 and Thunderbird :

GO to KB36 .

All others :

GO to KB34 . REPAIR short circuit. KB34 CHECK FP CIRCUIT IN FPDM

• Reconnect FPDM.
• Key on, engine off.
• Measure voltage between FP circuit at PCM harness connector pin and ground.

Is voltage between 4.5 and 5.5 volts?
Yes No REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPLACE FPDM. KB36 CHECK FPF PID

• Key on, engine off.
• Access the FP and FPF PIDs on the scan tool (the FP PID may be used in the next step).
• While viewing the FPF PID for 20 seconds, check if the FPF PID will indicate YES. The FPF PID may read NO in the 20 seconds, but will change back to YES.

Does the FPF PID indicate YES within 20 seconds?
Yes No GO to KB40 . GO to KB37 . KB37 CHECK FP PID

Does the FP PID indicate between 70 and 80%?
Yes No GO to KB38 . TURN KEY OFF then back ON. Wait 5 seconds. REPEAT test step. If result is now YES, follow YES result. If result is still NO, REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). KB38 ACCESS REM PIDS AND CHECK PWM_DC1 PID

• Access the PWM_DC1 PID from the REM menu (the PWM_DC1 PID indicates the signal sent to the REM from the PCM on the FP circuit).

Does the PWM_DC1 PID indicate between 70 and 80%?
Yes No KEY OFF. No fault indicated. Disregard DTC P1235 or P1236. RETURN to Section 3 where DTC was received and proceed as directed. REPLACE REM. KB40 CHECK REM CIRCUITRY VOLTAGE ON FP CIRCUIT AT PCM

• Key off.
• Disconnect PCM connector B (BODY).
• Key on, engine off.
• Measure voltage between pin B58 at PCM harness connector B and ground.

Is voltage greater than 8 volts?
Yes No REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPLACE REM. KB42 CHECK FP CIRCUIT FOR INTERMITTENT CONCERNS

• Key on, engine off.
• Access the REM PID access menu on the scan tool.
• Access the PWM_DC1 PID from the REM menu (the PWM_DC1 PID indicates the signal sent to the REM from the PCM on the FP circuit).
• Observe the PWM_DC1 PID for indication of a fault while completing the following (the PID value will change when a fault is detected):
  • Shake, wiggle and bend the FP circuit between the PCM (Pin B58) and REM (Pin J2-19).

Is a fault indicated?
Yes No ISOLATE fault and REPAIR as necessary. KEY OFF. Unable to duplicate or identify fault at this time. GO to Z1 with the following data: PWM_DC1 PID (REM menu), FP PID (PCM menu, the FP PID is the signal the PCM is sending to the REM). KB45 CHECK FP CIRCUIT FOR INTERMITTENT OPENS OR SHORTS

• Key on, engine off.
• Access FPM PID. Note: With no fault detected, the FPDM will send a 50% duty cycle signal (all OK) to the PCM on the FPM circuit. Depending on scan tools, the FPM PID may display 50%, or a random value that is fluctuating between 85 and 115%.
• Observe the FPM PID for an indication of a fault while completing the following (look for the FPM PID to change from the 50% value, or to stop fluctuating):
  • Shake, wiggle, bend the FP circuit between FPDM and the PCM.
  • Lightly tap on the FPDM (to simulate road shock).

Is a fault indicated?
Yes No ISOLATE fault and REPAIR as necessary. KEY OFF. Unable to duplicate or identify fault at this time. GO to Z1 . KB47 DTC P1237 OR P1238: IS DTC P1237 OR P1238 PRESENT IN KEY ON ENGINE OFF OR ENGINE RUNNING SELF TEST

Is DTC P1237 or P1238 present in Key On Engine Off or Key On Engine Running Self-Test?
Yes No A hard fault is present. GO to KB48 . DTC P1237 or P1238 is possibly intermittent.

For LS6/LS8 and Thunderbird :

GO to KB67 .

All others :

GO to KB56 . KB48 DOES THE ENGINE START?

Does the engine start?
Yes No For LS6/LS8 and Thunderbird :

GO to KB80 .

All others :

DISCONNECT FPDM. GO to KB59 . For LS6/LS8 and Thunderbird :

GO to KB61 .

All others :

GO to KB49 to check fuel pump secondary circuits. KB49 CHECK FP PWR, FP RTN AND INTERNAL FUEL PUMP CIRCUIT RESISTANCE

• Disconnect scan tool from DLC.
• Disconnect FPDM.
• Measure resistance between FP PWR circuit and the FP RTN circuit at the FPDM harness connector.

Is resistance less than 10.0 ohms?
Yes No GO to KB50 . An open secondary circuit exists. GO to KB54 to isolate fault. KB50 CHECK FP RTN CIRCUIT FOR SHORT TO POWER IN HARNESS

• Key on, engine off.
• Measure voltage between the FP RTN circuit in harness and chassis ground.

Is voltage less than 1.0 volt?
Yes No GO to KB51 . REPAIR short circuit. KB51 CHECK FP PWR CIRCUIT FOR SHORT TO GROUND IN HARNESS

• Disconnect fuel pump.
• Measure resistance between the FP PWR circuit in harness and ground.

Is resistance greater than 10,000 ohms?
Yes No GO to KB52 . REPAIR short circuit. KB52 CHECK FOR VOLTAGE TO FUEL PUMP

• Reconnect FPDM.
• Reconnect scan tool.
• Key on, engine off.
• Access Output Test Mode on scan tool. (To complete this test step without a scan tool, the fuel pump can be commanded on for one second by cycling the key from off to on. Repeat as needed.)
• Connect digital multimeter between the FP PWR circuit and the FP RTN circuit at the fuel pump harness connector.
• While monitoring voltage, command outputs on (this commands the fuel pump on for about 5 seconds).

With the fuel pump commanded on, is the voltage greater than 10.0 volts?
Yes No REPLACE fuel pump. VERIFY vehicle battery was at proper charge during test. VERIFY pump on command did not time-out before voltage check was made. If OK, REPLACE FPDM. KB54 ISOLATE OPEN CIRCUIT

• Disconnect fuel pump.
• Measure resistance of the FP PWR circuit between the FPDM and fuel pump harness connectors.
• Measure resistance of the FP RTN circuit between the FPDM and fuel pump harness connectors.
• Measure internal resistance of the fuel pump.

Is each resistance less than 10.0 ohms?
Yes No No fault is detected. VERIFY results of previous test steps. REPAIR open in appropriate circuit (if open was internal to pump, REPLACE fuel pump). KB56 VERIFY THAT DTC P1237 OR P1238 IS INTERMITTENT

• Note: When the FPDM is detecting a secondary fuel pump circuit fault (the wires going to the fuel pump), a 75% duty cycle signal will be sent to the PCM on the FPM circuit. On some scan tools, the FPM PID may display the 75% signal as a random value that is fluctuating between 250 and 400%.
• Key on, engine off.
• Access FPM PID.

Is the FPM PID 75% (or varying between 250 and 400%)?
Yes No A hard fault is present. GO to KB48 . DTC P1237 or P1238 is intermittent. GO to KB57 . KB57 CHECK FUEL PUMP SECONDARY CIRCUITS FOR INTERMITTENT OPEN OR SHORT

• Key on, engine off.
• Access FPM PID. Note: With no fault detected, the FPDM will send a 50% duty cycle signal (all OK) to the PCM on the FPM circuit. Depending on scan tools, the FPM PID may display 50%, or a random value that is fluctuating between 85 and 115%.
• Observe the FPM PID for an indication of a fault while completing the following (the FPM PID will change from the normal (all OK) reading when a fault is detected):
  • Shake, wiggle, bend the FP PWR circuit and FP RTN circuit between the FPDM and the fuel pump.
  • Lightly tap the fuel pump and the FPDM to simulate road shock.

Is a fault indicated?
Yes No ISOLATE fault and REPAIR as necessary. KEY OFF. GO to KB58 . KB58 CHECK FP PWR CIRCUIT FOR SHORT TO GROUND

• Disconnect FPDM.
• Connect a non-powered test lamp between the FP PWR circuit and the FPDM PWR circuit at the FPDM harness connector.
• Key on.
• Observe test lamp for an indication of a fault while completing the following (the test lamp will turn on when a fault is detected, indicating a short to ground):
  • Shake, wiggle, bend the FP PWR circuit between the FPDM and the fuel pump.

Is a fault indicated?
Yes No ISOLATE fault and REPAIR as necessary. KEY OFF. Unable to duplicate or identify fault at this time. RECONNECT FPDM. GO to Z1 . KB59 CHECK FP PWR CIRCUIT FOR SHORT TO POWER

• FPDM disconnected.
• Key on, engine off.
• Measure voltage between the FP PWR circuit at the FPDM harness connector and chassis ground.

Is voltage less than 1.0 volt?
Yes No GO to KB60 . REPAIR FP PWR circuit short to power. KB60 CHECK FP RTN CIRCUIT FOR SHORT TO GROUND

• FPDM disconnected.
• Key on.
• Measure voltage between the FPDM PWR and FP RTN circuits at the FPDM harness connector.

Is voltage less than 1.0 volt?
Yes No REPLACE FPDM. REPAIR FP RTN circuit short to ground. KB61 CHECK REM/FP PWR AND GROUND CIRCUIT TO REM PINS J1-1, J1-2

• Note: Verify inertia fuel shutoff (IFS) switch is not tripped.
• Disconnect REM connector J1.
• Key on.
• Measure voltage between pins J1-1 (REM/FP PWR) and J1-2 (GND) at the REM harness connector.

Is voltage greater than 10.5 volts?
Yes No KEY OFF. GO to KB49 (The FPDM functions are incorporated in the Rear Electronics Module (REM). In the following test steps, if directed to complete an action with the FPDM, complete the action with the REM. Refer to the pin numbers in the beginning of this pinpoint test). GO to KB62 . KB62 CHECK REM/FP PWR CIRCUIT VOLTAGE TO REM USING CHASSIS GROUND AS A REFERENCE

• Key on.
• Measure voltage between pin J1-1 of the REM harness connector and chassis ground.

Is voltage greater than 10.5 volts?
Yes No REPAIR open ground circuit in harness to pin J1-2 of the REM. KEY OFF. GO to KB63 . KB63 CHECK FOR B+ TO FUEL PUMP RELAY HARNESS CONNECTOR

• Disconnect fuel pump relay.
• Measure B+ circuit voltage at fuel pump relay harness connector.

Is voltage greater than 10.5 volts?
Yes No GO to KB64 . VERIFY condition of related fuse(s). If OK, REPAIR open circuit. If B+ fuse is damaged, CHECK for B+ short to ground or FP RTN for short to power before replacing fuse. KB64 CHECK FOR IGN START/RUN VOLTAGE (THROUGH IFS SWITCH) TO FUEL PUMP RELAY HARNESS CONNECTOR

• Disconnect REM connector J3.
• Key on.
• Measure IGN START/RUN circuit (from IFS switch) voltage at fuel pump relay harness connector.

Is voltage greater than 10.5 volts?
Yes No KEY OFF. GO to KB65 . VERIFY condition of related fuse. If fuse is damaged, CHECK for IGN START/RUN circuit short to ground before replacing fuse. If fuse is OK, GO to KB69 (to isolate open circuit). KB65 CHECK GROUND CIRCUIT TO FUEL PUMP RELAY

• Measure resistance of ground circuit between the fuel pump relay harness connector and ground.

Is resistance less than 5.0 ohms?
Yes No GO to KB66 . REPAIR open circuit. KB66 CHECK REM/FP PWR CIRCUIT CONTINUITY

• Measure resistance of REM/FP PWR circuit between the fuel pump relay harness connector and the REM harness connector (pin J1-1).

Is resistance less than 5.0 ohms?
Yes No REPLACE fuel pump relay. REPAIR open circuit. KB67 CHECK REM/FP PWR, REM GROUND AND CIRCUITS ASSOCIATED WITH THE FUEL PUMP RELAY FOR INTERMITTENTS

• Disconnect REM connector J1.
• Connect a non-powered test lamp between pins J1-1 (REM/FP PWR) and J1-2 (GND) of the REM harness connector.
• Key on.
• Observe test lamp for an indication of a fault while completing the following (the test lamp will go out when a fault is detected):
  • Shake, wiggle and bend the REM/FP PWR and GND (pin J1-2) circuits to REM.
  • Shake, wiggle and bend the circuits going to the fuel pump relay (IGN START/RUN, B+ ground).
  • Lightly tap the fuel pump relay and IFS switch to simulate road shock.

Is a fault detected?
Yes No ISOLATE fault and REPAIR as necessary. KEY OFF. GO to KB68 . KB68 CHECK FP PWR AND FP RTN CIRCUITS FOR INTERMITTENT CONCERNS

• Connect a DVOM (set to measure resistance) between pins J1-11 (FP PWR) and J1-12 (FP RTN).
• Observe DVOM for an indication of a fault while completing the following (resistance will change suddenly [from less than 10 ohms] when a fault is detected):
  • Shake, wiggle and bend the FP PWR and FP RTN circuits between the fuel pump and REM.
• Connect DVOM between pin J1-12 (FP RTN) and ground.
• Observe DVOM for an indication of a fault while completing the following (resistance will change suddenly [from greater than 10,000 ohms] when a short to ground is detected):
  • Shake, wiggle and bend the FP PWR and FP RTN circuits between the fuel pump and REM.

Is a fault indicated?
Yes No ISOLATE fault and REPAIR as necessary. KEY OFF. Unable to duplicate or identify fault at this time. REMOVE DVOM, RECONNECT REM. GO to Z1 . KB69 ISOLATE OPEN IN IGN START/RUN CIRCUIT

• Disconnect Inertia Fuel Shutoff (IFS) switch.
• Measure resistance across the normally closed contacts of the IFS switch. Note resistance.
• Measure resistance of IGN START/RUN circuit between the IFS switch and fuel pump relay harness connectors.

Are both resistances less than 5.0 ohms?
Yes No REPAIR open IGN START/RUN circuit to IFS switch. If open was in IGN START/RUN circuit, REPAIR open. If open was in IFS switch, REPLACE switch. KB70 SENT HERE FROM PINPOINT TEST HC WITH LOW VOLTAGE AT FUEL PUMP AND NO DTCs: CHECK BATTERY VOLTAGE WITH OUTPUTS COMMANDED ON

• Note: For LS6/LS8 and Thunderbird, verify REM Self-Test has been previously performed.
• Scan tool connected.
• Fuel pump disconnected.
• Key on.
• Connect digital multimeter to the battery positive and battery negative posts.
• While monitoring battery voltage, command outputs on. Note voltage within 5 seconds.
• Command outputs off.

Was battery voltage greater than 11.0 volts?
Yes No GO to KB71 . Battery voltage is low. REFER to Charging System, General Information Section 414-00 in the Workshop Manual. KB71 CHECK GROUND CIRCUIT TO FUEL PUMP BY MEASURING VOLTAGE AT FUEL PUMP USING BATTERY NEGATIVE AS A REFERENCE

• Connect digital multimeter between the FP PWR circuit at the fuel pump harness connector and the battery negative post.
• Key on.
• While monitoring voltage, command outputs on. Note voltage within 5 seconds.

Is voltage greater than 10.5 volts?
Yes No Ground fault to fuel pump indicated. CHECK all associated wiring and connections for the fuel pump and FPDM ground circuits. Carefully CHECK the FPDM ground connection to chassis ground. REPAIR as necessary. KEY OFF. Ground circuit to fuel pump is OK. GO to KB72 . KB72 CHECK VOLTAGE TO FUEL PUMP DRIVER MODULE (FPDM)

• Note: For LS6/LS8 and Thunderbird, the FPDM functions are incorporated in the Rear Electronics Module (REM). In the following steps, if directed to complete an action with the FPDM, complete the action with the REM.
• Disconnect fuel pump driver module (FPDM).
• Key on.
• Measure voltage between the FPDM PWR circuit at the FPDM harness connector and the battery negative post.

Is voltage greater than 10.5 volts?
Yes No KEY OFF. GO to KB73 . KEY OFF. Improper voltage is being supplied to FPDM. GO to KB75 . KB73 CHECK FP PWR CIRCUIT

• Connect a jumper wire between the FPDM PWR pin and FP PWR pin at the FPDM harness connector.
• Key on.
• Measure voltage between the FP PWR circuit at the fuel pump harness connector and the battery negative post.

Is voltage greater than 10.5 volts, AND within 0.5 volt of the reading in KB72?

Yes No KEY OFF. REMOVE jumper. VERIFY previous test steps. CHECK related connectors for corrosion, etc. If all checks are OK, REPLACE FPDM. KEY OFF. REMOVE jumper. CHECK for causes of high resistance in FP PWR circuit. KB75 CHECK B+ TO FPDM POWER SUPPLY RELAY (or CCRM)

• Disconnect CCRM (Escort, Mustang) or FPDM power supply relay (all others).
• Key on (to put same load on battery as previous steps).
• For Escort, Mustang:
  • Measure voltage between pin 11 (B+) of the CCRM harness connector and the battery negative post.
• For all others:
  • Measure voltage between the B+ circuit at the FPDM power supply relay harness connector and the battery negative post.

Is voltage greater than 10.5 volts?
Yes No KEY OFF. GO to KB76 . Improper voltage is being supplied to the CCRM or FPDM power supply relay. CHECK associated wiring, connectors, etc. REPAIR as necessary. KB76 CHECK FPDM PWR CIRCUIT

• For Escort, Mustang:
  • Connect a jumper wire between pin 11 (B+) and pin 5 at the CCRM harness connector.
• For all others:
  • Connect a jumper wire between the B+ and the FPDM PWR circuit at the FPDM power supply relay harness connector.
• Key on.
• Measure voltage between the FPDM PWR circuit at the FPDM harness connector and the battery negative post.

Is voltage greater than 10.5 volts?
Yes No VERIFY previous test steps. CHECK related connectors for corrosion, etc. If all checks are OK, REPLACE FPDM. CHECK for causes of high resistance in associated connectors and wiring of the FPDM PWR VPWR circuit, including the IFS switch and its connector. REPAIR as necessary. KB80 CHECK FP RTN CIRCUIT FOR SHORT TO GROUND

• Disconnect REM connector J1.
• Key on.
• Measure voltage between pins J1-1 and J1-12 at the REM harness connector.

Is voltage less than 1.0 volt?
Yes No GO to KB67 . REPAIR FP RTN circuit short to ground. KB85 COMPLETE REAR ELECTRONICS MODULE SELF-TEST TO VERIFY IFS SWITCH INPUT TO REM (REM PIN J3-8)

• Complete Rear Electronics Module Self-Test (refer to Workshop Manual section 419-10, Multifunction Electronic Control Modules, for directions).

Is REM DTC B2172 present?
Yes No GO to KB86 . GO to A1 . KB86 B2172: CHECK IFS SWITCH INPUT CIRCUIT TO REM (REM PIN J3-8)

• Disconnect REM connector J3.
• Key on, engine off.
• Measure voltage at pin J3-8 of the REM harness connector.

Is voltage greater than 10.5 volts?
Yes No KEY OFF.

If engine is a no start and REM DTC B2172 was received in on-demand self-test mode:

REPLACE REM.

If engine will start or REM DTC B2172 is a continuous memory DTC:

DTC is intermittent. If engine is a no start, return to Section 3 to continue diagnosis. If engine will start, GO to Z1 (even though PPT Z is designed for PCM intermittents, the diagnostic techniques will help with the REM diagnosis). KEY OFF. VERIFY IFS switch is not open. If OK, REPAIR open circuit between IFS switch and REM pin J3-8.










P0148 All — — GO to HC1
2003 PCED OBD
SECTION 5: Pinpoint Tests

Procedure revision date: 03/28/2003
HC: Fuel Delivery System

HC: Introduction HC1 CHECK SYSTEM INTEGRITY

• Visually inspect the complete fuel delivery system for damage; including fuel lines, connections, relays, fuel tank, fuel pump, fuel pressure regulator, fuel pulse damper and fuel injector areas for leaks, looseness, cracks, kinks, pinching, or abrasion caused by a collision or mishandling.
• Visually inspect electrical harness and connectors for loose pins, corrosion, abrasion, or other damage from collision or mishandling.
• Check electrical connectors for proper mating.
• Verify vehicle has followed maintenance schedule.
• Verify inertia fuel shutoff (IFS) switch is set.
• Verify battery is fully charged (12.5 volts or greater).
• Verify electrical/fuse integrity.
• Verify fuel level in the tank is sufficient.

Are any concerns present?
Yes No REPAIR as necessary. GO to HC2 . HC2 CHECK VOLTAGE AT FUEL PUMP HARNESS CONNECTOR

• Connect battery charger.
• Verify IFS switch state. Follow the IFS switch reset procedure at the beginning of this pinpoint test.
• Disconnect the fuel pump harness connector at the fuel pump.
• Key on, engine off.
• Connect a digital multimeter between the fuel pump power circuit and fuel pump ground circuit at the fuel pump harness connector (refer to the Wiring Diagram Manual for correct pin location).
• Access Output Test Mode (refer to Section 2 ) and turn on the fuel pump circuit and monitor the voltage reading.

Was the voltage greater than 12.5 volts?
Yes No KEY OFF. EXIT Output Test Mode. GO to HC3 . KEY OFF. FOR vehicles with electronic returnless fuel systems: GO to KB70 .

ALL others: CHECK for opens and shorts in the fuel pump power and ground circuits. HC3 CHECK FUEL FILTER FOR PROPER MAINTENANCE

• Locate and inspect the vehicle maintenance schedule and fuel filter. Check for last repair date.

Was the fuel filter replaced within the last 48,280 km/30,000 miles?
Yes No GO to HC4 . REPLACE fuel filter. GO to HC4 . HC4 CHECK FUEL PRESSURE

• 
  WARNING: BEFORE SERVICING OR REPLACING ANY COMPONENTS IN THE FUEL SYSTEM, REDUCE THE POSSIBILITY OF INJURY OR FIRE BY FOLLOWING DIRECTIONS IN FUEL SYSTEM CAUTION, HANDLING AND WARNING AT THE BEGINNING OF THIS PINPOINT TEST.
• Install fuel pressure tester.
• Release fuel pressure.
• Key on, engine off.
• Access Output Test Mode and run the fuel pump to obtain maximum fuel pressure. (GO to Pinpoint Test HC to refer to the Fuel System Specification Chart.) Note: The fuel pump will only operate for approximately 8 seconds when Output Test Mode is selected and activated.

Is the fuel pressure within the specified pressure range as stated in the Fuel System Specification Chart?
Yes No KEY OFF.GO to HC5 . KEY OFF. For Mechanical Returnless Fuel System with fuel pressure greater than 448 kPa (65 psi). REPLACE fuel pressure regulator in fuel tank.

For Mechanical Returnless Fuel System with fuel pressure less than 310 kPa (45 psi): GO to HC5 .

For Electronic Returnless Fuel Systems with fuel pressure greater than 448 kPa (65 psi). RERUN Quick Test. Other DTC's should be present if fuel pressure is out of range.

All others:

Fuel pressure greater than 280 kPa (40 psi) on Return Fuel Systems , GO to HC10 .

Fuel pressure less than 240 kPa (35 psi) on Return Fuel Systems , GO to HC5 . HC5 CHECK FUEL PRESSURE LEAKDOWN

• Observe Warning, Caution and Notes.
• Fuel pressure tester installed.
• Key on, engine off.
• Access Output Test Mode and run the fuel pump to obtain maximum fuel pressure.
• Key off.
• Verify fuel pressure remains within 34 kPa (5 psi) of the maximum fuel pressure for 1 minute after the fuel pump is turned off.

Does the fuel pressure remain within 34 kPa (5 psi)?
Yes No Return Fuel Systems , GO to HC7 . All others , GO to HC12 .
GO to HC6 . HC6 CHECK PRESSURE REGULATOR AND PULSE DAMPER DIAPHRAGM

• Fuel pressure tester installed.
• Start engine and run engine for 10 seconds.
• Key off, wait 10 seconds.
• Start engine and run engine for 10 seconds.
• Key off, remove vacuum hose from fuel pressure regulator or pulse damper port.
• Inspect for fuel in the vacuum hose or regulator port or pulse damper.

Is fuel present in the vacuum hose, regulator or pulse damper port?
Yes No REPLACE fuel pressure regulator.

For Mechanical Returnless Fuel System:

Replace pulse damper. For Mechanical Returnless:

GO to HC13 .

All others:

GO to HC12 . HC7 CHECK FUEL PRESSURE, ENGINE RUNNING

• Fuel pressure tester installed.
• Disconnect vacuum hose at the fuel pressure regulator and plug it.
• Drive vehicle with heavy accelerations while observing fuel pressure gauge reading.

Does fuel pressure reading hold steady within 21 kPa (3 psi) during test?
Yes No GO to HC8 . GO to HC13 . HC8 CHECK FUEL PRESSURE REGULATOR RESPONSE

• Fuel pressure tester installed.
• Install vacuum gauge to intake manifold.
• Start engine and observe both gauges.
• Accelerate and decelerate engine speed to vary vacuum gauge reading.

Does the fuel pressure gauge reading increase as vacuum gauge reading decreases or decrease as vacuum gauge reading increases?
Yes No Concern is elsewhere. RETURN to Section 3 , Symptom Charts for further direction. GO to HC9 . HC9 CHECK VACUUM SUPPLY

• Fuel pressure tester installed.
• Vacuum hose disconnected and plugged at the fuel pressure regulator.
• Install a hand held vacuum pump to the fuel pressure regulator.
• Start engine, remain at idle.
• Observe fuel pressure while applying vacuum.

Does the fuel pressure change as the vacuum changes?
Yes No REPAIR vacuum source. REPLACE fuel pressure regulator. HC10 CHECK FOR RESTRICTED FUEL RETURN LINE

• Fuel pressure tester installed.
• Remove fuel return line at the fuel rail and connect a short hose from the fuel rail to a measure container of at least 1.1 liter (1.0 quart) capacity.
• Key on, engine off.
• Access Output Test Mode and run the fuel pump to obtain maximum fuel flow (one cycle of the fuel pump is all that is required).
• Record fuel pressure and observe if fuel is being returned to the measuring container.

Is fuel pressure within specification and is fuel returning to the container?
Yes No KEY OFF. GO to HC11 . KEY OFF. Fuel pressure out of specification. REPLACE fuel pressure regulator. HC11 CHECK FUEL RETURN SYSTEM

• Observe Warning, Caution and Handling at the beginning of this pinpoint test.
• Disconnect fuel return line at the fuel rail.
• Disconnect fuel return line at the fuel pump.
• Check the fuel return line for restrictions due to blockage, kinking or pinching.
• Apply 21 to 34 kPa (3 to 5 psi) regulated shop air to the return line pressure.

Does air flow freely through the line?
Yes No REPLACE the fuel pump module. REPAIR the fuel return line. HC12 CHECK FUEL INJECTOR FLOW AND LEAKAGE

• Observe Warning, Caution and Handling at the beginning of this pinpoint test.
• Check injectors for leakage and flow rate using Injector Flow Tester.

Are test results satisfactory?
Yes No For symptoms without DTCs and Electronic/Mechanical Returnless Fuel Systems: RETURN to Section 3 , Symptom Charts for further direction.

All others: VERIFY no other leak exists. REPLACE fuel pump module. REPLACE faulty fuel injector(s). HC13 CHECK FUEL SUPPLY LINE FOR RESTRICTION

• Observe Warning, Cautions and Handling at the beginning of this pinpoint test.
• Disconnect fuel supply line at the fuel rail.
• Disconnect fuel supply line at the fuel pump.
• Check the fuel supply line for restrictions due to blockage, kinking, or pinching.
• Apply 21 to 34 kPa (3 to 5 psi) regulated shop air pressure to the supply line.

Does air flow freely through the line?
Yes No Air flows freely. REPLACE fuel pump module. REPAIR cause of restriction.

 

[hotcobra03]

heres a link thats passed around alot


WestCoastMustangs.com

 

[Black306]

Other than the pumps, what have you upgraded in the fuel system?

A P1237 code is basically the FPDM telling the ECU that there is a problem between the FPDM and pumps. So you are going to have a problem with the pumps, the FPDM to pump wires, and/or the FPDM. However, my experience with P1237 codes caused by FPDMs don't cause a non-start issue. The circuitry relating to the return signal is damaged but doesn't affect the operation of the pump. So more than likely, your issue is pump or wiring related. But don't completely rule out the FPDM. Also, that code won't pop up with a hose issue.

 

[SVT356393]

heres a link thats passed around alot


WestCoastMustangs.com

Thanks for the link, going to use that today while dropping the tank. Am going to check the wiring by the fuel pump to see if it's a wiring problem then of course check the pump itself.

Other than the pumps, what have you upgraded in the fuel system?

A P1237 code is basically the FPDM telling the ECU that there is a problem between the FPDM and pumps. So you are going to have a problem with the pumps, the FPDM to pump wires, and/or the FPDM. However, my experience with P1237 codes caused by FPDMs don't cause a non-start issue. The circuitry relating to the return signal is damaged but doesn't affect the operation of the pump. So more than likely, your issue is pump or wiring related. But don't completely rule out the FPDM. Also, that code won't pop up with a hose issue.

I have a new fuel filter from AM that is also going to be replaced. We'll have to see on what the problem is but I did also get the fuel delivery error. Even then though, my pump isn't priming. I'm starting to think this guy was yanking my chain about having a twin fuel pump setup while the wiring and fpdm are stock. Then again that could be whats causing all the problems. I'll narrow it down this afternoon and keep ya'll updated. Is there anything to look for when you open the FPDM, as far as damage to the circuit board? It looks to be in pretty good shape.

 

[hotcobra03]

good luck,,i was looking for a recent thread,same 2 codes,same story except he was gas station,

his was pprv thing hose was off,,

how full is tank?

might sound dump but have you tried pump direct?

i had full tank when head went,needed gas for rental car,,

i used connector at rear bumper,than unhooked fuel line at old school connector just below passenger valve cover,added hose to can,,used a battery at connector,,


this is a test also to see if pumps work,,

 

[Black306]

I have a new fuel filter from AM that is also going to be replaced. We'll have to see on what the problem is but I did also get the fuel delivery error. Even then though, my pump isn't priming. I'm starting to think this guy was yanking my chain about having a twin fuel pump setup while the wiring and fpdm are stock. Then again that could be whats causing all the problems. I'll narrow it down this afternoon and keep ya'll updated. Is there anything to look for when you open the FPDM, as far as damage to the circuit board? It looks to be in pretty good shape.

Damage to an FPDM that causes a P1237 code won't be obvious. The only physical damage you might see will look like this:

But these types of failures usually only show up as drivability issues, not a non-working pump.

If you have upgraded pumps with a stock FPDM and wiring, that could be the cause of the problem. A stock FPDM wasn't designed to handle the current of upgraded pumps and neither was the wiring. With FPDMs, you usually just get a thermal shutdown condition where the FPDM gets too hot to manage the pumps. But the FPDM usually starts working again after a few seconds to a few minutes after it has had a chance to cool down. With wiring, I have seen the underside of a stock hat fry from too much current.

I would suggest pulling the hat out and first making sure if you have upgraded pumps. If so, make additional modifications as needed.

 

[SVT356393]

Damage to an FPDM that causes a P1237 code won't be obvious. The only physical damage you might see will look like this:

But these types of failures usually only show up as drivability issues, not a non-working pump.

If you have upgraded pumps with a stock FPDM and wiring, that could be the cause of the problem. A stock FPDM wasn't designed to handle the current of upgraded pumps and neither was the wiring. With FPDMs, you usually just get a thermal shutdown condition where the FPDM gets too hot to manage the pumps. But the FPDM usually starts working again after a few seconds to a few minutes after it has had a chance to cool down. With wiring, I have seen the underside of a stock hat fry from too much current.

I would suggest pulling the hat out and first making sure if you have upgraded pumps. If so, make additional modifications as needed.

So check the fuel hat, if that's fried then I'm looking at new fpdm, wiring harness, fuel hat, and possibly pumps?

 

[hotcobra03]

Damage to an FPDM that causes a P1237 code won't be obvious. The only physical damage you might see will look like this:

But these types of failures usually only show up as drivability issues, not a non-working pump.

If you have upgraded pumps with a stock FPDM and wiring, that could be the cause of the problem. A stock FPDM wasn't designed to handle the current of upgraded pumps and neither was the wiring. With FPDMs, you usually just get a thermal shutdown condition where the FPDM gets too hot to manage the pumps. But the FPDM usually starts working again after a few seconds to a few minutes after it has had a chance to cool down. With wiring, I have seen the underside of a stock hat fry from too much current.

I would suggest pulling the hat out and first making sure if you have upgraded pumps. If so, make additional modifications as needed.

pics..epper::beer:

 

[Black306]

So check the fuel hat, if that's fried then I'm looking at new fpdm, wiring harness, fuel hat, and possibly pumps?

You shouldn't need an FPDM or pumps if the hat is fried. Just replace/repair/modify the stock hat. But definitely upgrade the wiring.

 

[Black306]

pics..epper::beer:

Commenting on the pics or are you looking for pics? :??:

 

[hotcobra03]

Commenting on the pics or are you looking for pics? :??:

commenting pics,its nice to see,,have saved other pics from members,,they are helpful

 

[SVT356393]

Looking at a new fuel hat, wiring, and pumps. Any recommendations on the setup to run? Was planning on DivisionX Fuel hat w/ pigtail (same as what I'm working with now) and I'm stumped on fuel pumps and how to keep this from happening again other than running two fpdm's.

 

[SVT356393]

Or possible run the budget return??