Speedometer bouncing and car bucking

shurur

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Ok...so I plan to start troubleshooting this weekend. I need our backup car running!!

I plan is to fix speedo problem and see what goes from there. Problem is intermittent...and speedo working makes bucking go away...so problems appear to be related.

1. Run torque app to see if speedo works in app.
A. If speedo works in torque app, problem is not speed sensor. ( speedcal is involved)
B. If speedo does not work in torque app problem is speed sensor...done.

2. Check power to speedcal.
A. If power (traction control) is not to speedcal...troubleshoot power problem ( new troubleshooting branch..whew!!)
B. If power (traction control..switched) is going to speedcal then bypass speedcal to see if speedo "works" with wrong rpm and see whether bucking goes away...now I have the perfect excuse with Wife to buy sct Steeda tuner to change gear ratio and dump speedcal altogether.

Normally I do not share or trust others with my troubleshooting process..but I am exhausted with other shit in my life....mainly getting work again (position eliminated due to late hire) as a HCPS FL teacher...****ing with this car is not "fun" anymore.

Any input, however abusive, is good input...**** it
I want to knock this out this weekend and get Kelly running again.
 
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shurur

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Also...posts on the net for similar problems are suck with no follow-up by OPs.
 
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01yellercobra

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I think you're on the right track with checking the speed sensor. At least for the speedo issue.

I can't see the speedo making the car buck. Unless it's a grounding issue causing both problems.
 

shurur

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ok..I figure the speedo is the easy fix.
I have seen several threads with both symptoms together; so hope the two are somehow related.

THANKS
 

01yellercobra

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They might be related. But lately I've been dealing with the speedo bouncing above 60mph with the MS3. While the speedo is moving around the car drives fine. Granted the MS3 might have the signals separated as I can view my speed other ways and its stable. So maybe the ECU is seeing the speed changing and freaking out.
 

Badaz01

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They might be related. But lately I've been dealing with the speedo bouncing above 60mph with the MS3. While the speedo is moving around the car drives fine. Granted the MS3 might have the signals separated as I can view my speed other ways and its stable. So maybe the ECU is seeing the speed changing and freaking out.
My ecu is gonna be freaking out in a couple weeks when it sees my speed changing after slapping on the procharger. lol.
 

shurur

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Ok....sooo..I replaced the speed sensor on the transmission and nothing has changed.

Speedometer still bounces or floats high as I drive.

I am exhausted from climbing around under the damn car. I changed diffy and tranny fluids while I was under there. Many many bs things to deal with while doing that

I going to get the speedcal out of the equation next.

Does anyone have schematics of how the speedcal is wired into the sensor and speedo meter???????

It is pretty confusing. I had thought it was in series and between with the speed sensor and the cluster...but I only see one connector....like it runs parallel with the sensor somehow. It makes no sense.

I did not originally install this and the instructions suck.

I need a top view of this with schematics, rather than instructions that I have to reverse read.

I need to eliminate the speedcal, before I go ripping out the cluster.

Aside:
This may be my excuse to get the ratio fixed in the ecu instead. I will be going SCT...I am tired of dIy soldering and other BS (Like Moates would be and the speedcal is) in my car. This hokey shit has got to go either way.
 

Badaz01

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Ok....sooo..I replaced the speed sensor on the transmission and nothing has changed.

Speedometer still bounces or floats high as I drive.

I am exhausted from climbing around under the damn car. I changed diffy and tranny fluids while I was under there. Many many bs things to deal with while doing that

I going to get the speedcal out of the equation next.

Does anyone have schematics of how the speedcal is wired into the sensor and speedo meter???????

It is pretty confusing. I had thought it was in series and between with the speed sensor and the cluster...but I only see one connector....like it runs parallel with the sensor somehow. It makes no sense.

I did not originally install this and the instructions suck.

I need a top view of this with schematics, rather than instructions that I have to reverse read.

I need to eliminate the speedcal, before I go ripping out the cluster.

Aside:
This may be my excuse to get the ratio fixed in the ecu instead. I will be going SCT...I am tired of dIy soldering and other BS (Like Moates would be and the speedcal is) in my car. This hokey shit has got to go either way.
So your gear ratio is not tuned into your ecu? If that’s the case no wonder it’s fouled up. I have sct tuner and I was able with about 5 minutes and a push of a button calibrate/tune my speedo for my 410’s and 18 inch wheels.
 

shurur

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So your gear ratio is not tuned into your ecu? If that’s the case no wonder it’s fouled up. I have sct tuner and I was able with about 5 minutes and a push of a button calibrate/tune my speedo for my 410’s and 18 inch wheels.

The speedcal adjusts for a change in the gear ratio. It is used instead of changing it in the ecu.
Look it up. The speedcal has been around for a while, although it is not made anymore. It was the go to device for many years. And there are folks still looking to buy them used.

I just want to eliminate it from the equation as I troubleshoot this thing.

If I remove the speedcal and the speedometer works (yes the speedo will not be working accurately fir my 3.73..but will work and not bounce or float or whatever it is doing now), then I will know the problem is not the cluster.

Ground is good btw.

I am looking for a wire diagram for the speedcal install, as a picture paints (replaces) a lousy thousand word set of install instructions.

I am also so happy for you that you could afford an SCT tuner and a procharger...good for you.
 
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Badaz01

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The speedcal adjusts for a change in the gear ratio. It is used instead of changing it in the ecu.
Look it up. The speedcal has been around for a while, although it is not made anymore. It was the go to device for many years. And there are folks still looking to buy them used.

I just want to eliminate it from the equation as I troubleshoot this thing.

If I remove the speedcal and the speedometer works (yes the speedo will not be working accurately fir my 3.73..but will work and not bounce or float or whatever it is doing now), then I will know the problem is not the cluster.

Ground is good btw.

I am looking for a wire diagram for the speedcal install, as a picture paints (replaces) a lousy thousand word set of install instructions.

I am also so happy for you that you could afford an SCT tuner and a procharger...good for you.
Thanks man yea I work my ass off 7 days a week for the last 14 years to finally be able to afford those things.
 

Badaz01

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The speedcal adjusts for a change in the gear ratio. It is used instead of changing it in the ecu.
Look it up. The speedcal has been around for a while, although it is not made anymore. It was the go to device for many years. And there are folks still looking to buy them used.

I just want to eliminate it from the equation as I troubleshoot this thing.

If I remove the speedcal and the speedometer works (yes the speedo will not be working accurately fir my 3.73..but will work and not bounce or float or whatever it is doing now), then I will know the problem is not the cluster.

Ground is good btw.

I am looking for a wire diagram for the speedcal install, as a picture paints (replaces) a lousy thousand word set of install instructions.

I am also so happy for you that you could afford an SCT tuner and a procharger...good for you.
I have also seen gauges bouncing in the past when I had alternator issues on my beat up old Chevy cavalier when I was 16.
 

shurur

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Thanks man yea I work my ass off 7 days a week for the last 14 years to finally be able to afford those things.

Me too..then had it all stolen from me in one night...sooo.

I am a dairy farmer's son. I didn't even start middleclass and was middleclass for only 10 years of my life.

Most everybody works hard..it just doesn't work out for us all. Please don't assume that everyone who has less than you is not a hard worker.

The speedcal was the poor folks solution to changing gears and getting it to work with the speedometer.
 

Badaz01

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Me too..then had it all stolen from me in one night...sooo.

I am a dairy farmer's son. I didn't even start middleclass and was middleclass for only 10 years of my life.

Most everybody works hard..it just doesn't work out for us all. Please don't assume that everyone who has less than you is not a hard worker.

The speedcal was the poor folks solution to changing gears and getting it to work with the speedometer.
I don’t assume anything I’ve done a heck of a lot worse work than I do now for less. Money isn’t everything. I hope you find the solution you are looking for. I’ll ask my tuner about speed cal next time I talk to him. Thanks for serving the public in the capacity you and your father do guys like yourselves don’t get enough credit.
 

shurur

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Ok.
Not fixed yet.
This is what I have so far.

I have the Haynes manual and the 1999 ford oem wiring manual as well.


OSS signal
1. I replaced the OSS sensor
2. I cut out the speedcal in order to eliminate it from the equation.
3. I jumpered the white to blue and the green to gray wires.
4. I disconnected the OSS connector and ran a continuity check to C106. It checked out fine.

Per the haynes manual, the OSS/VSS signal also goes to the speeedometer and the speed control (cruise control), but this is not so by observation and by the ford wiring diagrams.

There are two connectors going in to the cluster.

None has a OSS/VSS signal going in by continuity check or for diagrams. The only signal is for the tach; it is tan/ong..and is the positive data link.

That is why I think the data link is also used for the speedometer as well.

Again, It appears to me that the speedometer is feed by the data link signals...as it appears to be used by the tach. (????).

The next thing for me is to button it up and run cluster diagnostics. I should have done that in the beginning!!

So that is where I am at.
 
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shurur

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Unreated Side question....it is my thread afterall.

Does anyone know what the electronic box is that sets on top of the transmission tunnel, under the dash, inside the car?? It is next to the datalink port and has a connector with a locking red tab.

I can't find it in any documentation so far.
 
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DSG2003Mach1

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Unreated Side question....it is my thread afterall.

Does anyone know what the electronic box is that sets on top of the transmission tunnel, under the dash, inside the car?? It is next to the datalink port and has a connector with a locking red tab.

I can't find it in any documentation so far.

pic might be helpful
 

mwolson

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You are on the right track. In 99+ cars, the PCM reads the OSS, calculates the speed and sends it to the instrument cluster in digital form via the data bus. Here's a video I made that shows you how to test an OSS. You just need a piece of steel and an AC voltmeter:
Reading the speed from the PCM with a scanner can also prove that the OSS is working and that the PCM is able to read it.

When you power up the cluster, all of the gauges should do a full sweep. That full sweep doubles as both a self test and it ensures that the needle starts at 0 RPMs when it first powers up. It does that when I first apply power to a cluster on the bench. I can't remember if you have to remove all power to the cluster or if just turning the key off and then on again will trigger that self test.

Hope this helps.
 

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