PO443 code. Filled up yesterday evening at Kroger gas station and used 93 octane.

MustangSteve1965

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Filled it all the way up but did NOT top it off. Soon as the hose clicked off, I removed it.

When I started it up the check engine light came on and went to O'Reilly's and scanned it and the PO443 code showed up.

Is it the Kroger gas, LOL? Filling it all the way up? Both?

I'm fairly certain is has to be one of the two as it wasn't on until right after I filled.

Thanks!
 
Vinnie_B

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Evaporative Emission (EVAP) Systems​


The EVAP system prevents fuel vapor build-up in the sealed fuel tank. Fuel vapors trapped in the sealed tank are vented through the vapor valve assembly on top of the tank. The vapors leave the valve assembly through a single vapor line and continue to the EVAP canister for storage until the vapors are purged to the engine for burning.

P0443 - Evaporative Emission System Purge Control Valve Circuit


The PCM monitors the state of the EVAPCP circuit output driver. This DTC sets when the signal moves outside the minimum or maximum limit for the commanded state.


Possible Causes:

  • VPWR circuit open
  • EVAPCP circuit open
  • EVAPCP circuit short to ground
  • EVAPCP circuit short to voltage
  • Damaged EVAP purge valve
  • Damaged PCM

Diagnostic Aids:

To verify normal function, monitor the EVMV PID or EVAPCP PID and the signal voltage (PCM control side). With the valve closed, the EVMV indicates 0 mA (0% duty cycle for EVAPCP) and voltage approximately equal to battery voltage. When the valve is commanded fully open, EVMV indicates 1,000 mA (100% duty cycle for EVAPCP) and a voltage drop of 3 volts minimum is normal.
 
MustangSteve1965

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Vinnie_B said:

Evaporative Emission (EVAP) Systems​


The EVAP system prevents fuel vapor build-up in the sealed fuel tank. Fuel vapors trapped in the sealed tank are vented through the vapor valve assembly on top of the tank. The vapors leave the valve assembly through a single vapor line and continue to the EVAP canister for storage until the vapors are purged to the engine for burning.

P0443 - Evaporative Emission System Purge Control Valve Circuit


The PCM monitors the state of the EVAPCP circuit output driver. This DTC sets when the signal moves outside the minimum or maximum limit for the commanded state.


Possible Causes:

  • VPWR circuit open
  • EVAPCP circuit open
  • EVAPCP circuit short to ground
  • EVAPCP circuit short to voltage
  • Damaged EVAP purge valve
  • Damaged PCM

Diagnostic Aids:

To verify normal function, monitor the EVMV PID or EVAPCP PID and the signal voltage (PCM control side). With the valve closed, the EVMV indicates 0 mA (0% duty cycle for EVAPCP) and voltage approximately equal to battery voltage. When the valve is commanded fully open, EVMV indicates 1,000 mA (100% duty cycle for EVAPCP) and a voltage drop of 3 volts minimum is normal.
Click to expand...
Thank you. So it couldn't be caused by the gas or filling up the tank all the way? Seems a weird coincidence that it happened immediately after filling up.
 
Vinnie_B

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MustangSteve1965 said:
Thank you. So it couldn't be caused by the gas or filling up the tank all the way? Seems a weird coincidence that it happened immediately after filling up.
Click to expand...
I dont think putting gas in your shelby set this DTC. You got something going on in EVAP Purge Control Valve Circuit. Your might need someone to check the EVAP system.



Evaporative Emission (EVAP) Purge Valve

The EVAP purge valve (located near the engine) is part of the enhanced EVAP system controlled by the PCM. This valve controls the flow of vapors (purging) from the EVAP canister to the intake manifold during various engine operating modes. The EVAP purge valve is a normally closed valve. The PCM outputs a duty cycle between 0% and 100% to control the EVAP purge valve.


Typical EVAP Purge Valve


imagen2.dll

ItemNumberDescription
1—Fuel Vapor To EVAP Canister
2—Fuel Vapor To Intake Manifold
 
Vinnie_B

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This is how your EVAP system works.



Enhanced Evaporative Emission (EVAP) System

The enhanced EVAP system consists of a fuel tank, fuel filler cap or capless fuel tank filler pipe, fuel tank mounted or inline fuel vapor control valve, fuel vapor vent valve, EVAP canister, fuel tank mounted or fuel pump mounted or inline fuel tank pressure (FTP) sensor, EVAP purge valve, EVAP check valve (turbocharged engines only), intake manifold hose assembly, EVAP canister vent valve, PCM and connecting wires, and fuel vapor hoses. The enhanced EVAP system, including all the fuel vapor hoses, can be checked when a leak is detected by the PCM.

  1. The enhanced EVAP system uses inputs from the ECT sensor or cylinder head temperature (CHT) sensor, the IAT sensor, the MAF sensor, the VSS and the FTP sensor to provide information about engine operating conditions to the PCM. The PCM uses the FLI and FTP sensor signals to determine activation of the EVAP leak check monitor based on the presence of vapor generation or fuel sloshing.
  2. The PCM determines the desired amount of purge vapor flow to the intake manifold for a given engine condition. The PCM then outputs the required signal to the EVAP purge valve. The PCM uses the enhanced EVAP system inputs to evacuate the system using the EVAP purge valve, seal the enhanced EVAP system from the atmosphere using the EVAP canister vent valve, and uses the FTP sensor to observe total vacuum lost for a period of time.
  3. The EVAP canister vent valve seals the enhanced EVAP system to atmosphere during the EVAP leak check monitor.
  4. The PCM outputs a duty cycle between 0% and 100% to control the EVAP purge valve.
  5. The FTP sensor monitors the fuel tank pressure during engine operation and continuously transmits an input signal to the PCM. During the EVAP monitor testing, the FTP sensor monitors the fuel tank pressure or vacuum bleed-up.

    On some vehicles, a vapor blocking valve is used to isolate the fuel tank from the rest of the EVAP system for more efficient canister purging.
  6. A valve inside the fuel tank-mounted fuel vapor tube assembly prevents liquid fuel from entering the EVAP canister and the EVAP purge valve under any vehicle altitude, handling, or rollover condition.
  7. On turbocharged engines, the EVAP check valve prevents boost pressure from entering the EVAP system.
  8. On turbocharged engines, the turbocharger creates boost pressure in the intake manifold.
  9. On turbocharged engines, an EVAP ejector (if equipped) is used to create a vacuum in the purge line during boost conditions. When in boost conditions a percentage of the boost pressure is applied to the EVAP ejector to create a vacuum. This vacuum draws purge vapors through the EVAP ejector into the intake air system upstream of the turbocharger.


imagen2.dll
 
Last edited:
03cobra#694

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Would a gas cap trigger this? Evap crap is PITA sometimes. I gave up on a 04 Escape that had these codes constantly.
 
MustangSteve1965

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Vinnie_B

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03cobra#694 said:
Thanks Vinnie, I wasn't sure what year they started that.
Click to expand...
No problem. They don't come with caps standard but I have one just in case these issues like this don't happen with these newer designs. I personally don't like them!
 
Vinnie_B

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MustangSteve1965 said:
So, just turned the car on and the check engine light is now gone?

Also, this is probably insane to ask, but I’m in Michigan and right now the air quality is horrible because of the forest fires in Canada. No clue if that has anything to do with it?


Sent from my iPhone using the svtperformance.com mobile app
Click to expand...
No...I don't think so @MustangSteve1965. So what's happening now with no CEL is the pcm didn't see a issue this key cycle. Keep an eye out if nothing resurfaces don't worry about it. If it comes back let me know. I'm in Dearborn I have everything needed to diagnose this electrical gremlin if it returns. Just let me know.



 
MustangSteve1965

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