Trans Prob, 150 miles from home, Help (Bakersfield, CA)

[BigRigTech]

An ohm meter works just fine on a speed sensor, the sensor induces an A/C voltage which is read by the ecm - exactly the same idea as an ABS wheel speed sensor. If you have a resistance in the correct range then the sensor is good. Did you check the wiring from the sensor back to the PCM for opens, high resistance or shorts?

 

[psychohawk]

By any chance is your rig at Diesel Tune in Downey Ca... If so Mike really knows what he's talking about.

Yep ... truck has already been there a few times for other things ... hopefully Mike can help me figure this out. Sorry to hear about your friend/cousin/bad experience ... the place has been great for me though!

Did you check the wiring from the sensor back to the PCM for opens, high resistance or shorts?

No, haven't ... at this point I feel it's better left to the professionals ... I'm all for working on my truck and learning to prevent me from getting stuck, but I'm far from being a mechanic.

Thanks for the advice, I'll update when I learn what's going on,
Carl

PS I should mention ... about 1 week before the trans problem happened, my hood flew open on the freeway ... I'm beginning to wonder if this event pinched/shorted/broke wire that just took some time to materialize ... if I could only be so lucky.

 

[OLDBULL8]

PS I should mention ... about 1 week before the trans problem happened, my hood flew open on the freeway ... I'm beginning to wonder if this event pinched/shorted/broke wire that just took some time to materialize ... if I could only be so lucky.

I doubt very much if that would have anything to do with it. I towed my 92 10 miles with the hood up, Woops, all it did was bend the hood. Tranny E4OD works just great after that. Truck was up on a GN trailer to high to see the hood in the rearview mirror.

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[psychohawk]

IT'S FIXED!!

Well, thanks to everyone that insisted it a electronic issue! Heeding that advice, I brought the truck to a second mechanic for a second opinion and he was of the same opinion as everyone here: focus on the electronics first!

Turned out to be a relay on the firewall that controls the computer. Apparently a PO installed it upside down, it was full of water, corroded and not sending power to the main computer. Turned out a hellaofa lot cheaper than a trans!!

Thanks everyone!

 

[BigRigTech]

Good to hear, the sprague just didn't make sense to a lot of us...A cheap fix is always the best. You have to wonder how many people are screwed over daily for stuff like this.

 

[huse]

I've got the same problem in my truck..

I have checked just about everything.
Don't really know what more to check.
My tach is not working, It moves a tiny bit if i slam the throttle. Ocationally it bounces up and down.
My "rear antilock" light stays on.
And on my transmission only 2 gear works (limp mode).
My Truck is a 1990 F250 7.3idi e40d tranny.

This is what i have done so far:

• replaced the Rpm/Tach sensor with a new one- didn't help

• checked the Wires from the rpm/tach sensor to the tcm -ok

• checked the signal from the rpm/tach sensor at the connector for the tcm-ok

• checked for voltage and earth to the tcm-ok

• removed and opened the tcm to check see if i could see any problem- looked ok.

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• Removed the instrument cluster and checked for ground and voltage to tach, also checked the tach/rpm signal, Voltage and ground. voltage and ground- ok, tach signal is not ok (around 60-80mV) should be 300 mV or more

• tcm power relay has power going to it (yellow wire), the red wire (power) going to the tcm from the relay have power when ignition is on, relay ground is good (black wire).

Anyone that have an idea what it could be? What should i check next?
Should i get a new tcm? Is there any known issues conserning tcm failure?
What else would mess up the tach?

 

[trackspeeder]

IT'S FIXED!!

Well, thanks to everyone that insisted it a electronic issue! Heeding that advice, I brought the truck to a second mechanic for a second opinion and he was of the same opinion as everyone here: focus on the electronics first!

Turned out to be a relay on the firewall that controls the computer. Apparently a PO installed it upside down, it was full of water, corroded and not sending power to the main computer. Turned out a hellaofa lot cheaper than a trans!!

Thanks everyone!

Cool, Nice when the fix is cheap.

 

[OLDBULL8]

[PS I should mention ... about 1 week before the trans problem happened, my hood flew open on the freeway ... I'm beginning to wonder if this event pinched/shorted/broke wire that just took some time to materialize ... if I could only be so lucky. /QUOTE]

Never rains in Kali. Except in the last couple of weeks or so.

Must have been raining the day the hood flew open. Flooded the relay eh.

Glad you got it fixed.

It's a dirty shame a guy can't trust most of the transmission repair shops. Seems like there out for the money.

 

[FORDF250HDXLT]

IT'S FIXED!!

Well, thanks to everyone that insisted it a electronic issue! Heeding that advice, I brought the truck to a second mechanic for a second opinion and he was of the same opinion as everyone here: focus on the electronics first!

Turned out to be a relay on the firewall that controls the computer. Apparently a PO installed it upside down, it was full of water, corroded and not sending power to the main computer. Turned out a hellaofa lot cheaper than a trans!!

Thanks everyone!

there ya go.
now you know which trans shop to stay away from,and to inform all your family and friends to do the same.be sure to praise the honest shop while your at it.
you also know who to turn to for a rebuilt trans when the time really comes.


one more time for emphasis.

its human nature to jump to the worst case scenario.the problem is,it could cost ya more money than necessary.

 

[icanfixall]

Glad you got it corrected and running. Problem with breaking down far from home is the vultures are just waiting for dinner to drop in their laps. How can you tell some unknown mechanic is giving you the truth...

 

[Black dawg]

Glad you got it corrected and running. Problem with breaking down far from home is the vultures are just waiting for dinner to drop in their laps. How can you tell some unknown mechanic is giving you the truth...

the same way you can tell if some unknown customer is giving you the truth. you cant. sometimes you just have to make a judgment of thier character.

 

[OLDBULL8]

the same way you can tell if some unknown customer is giving you the truth. you cant. sometimes you just have to make a judgment of thier character.

I set here pondering your answer to icanfixall's statement. It must be directed to the author of this thread.
Why would any customer lie to a repair shop when they are broke down and need help?
I was in the RV repair service business for 15 yrs. Never once in all that time did I ever judge anyone on there character. Why would I?
Any reputable shop would ask questions. Any customer would surely try to tell what is wrong. If I didn't understand what they were saying, more questions were in order
Now pertaining to this thread.
If psychohawk told the shop what he posted here, about the tach and the speedo acting up and they made a diagnose that the sprag was shot in my judgement they don't know what there doing. Especially when the symtoms pointed to an electrical problem. A E4OD don't go into limp mode if the sprag is shot, that's a tow job.

 

[Black dawg]

RE shifts: I think someone misunderstood ... doesn't work in D at all, just "manual" 1st, 2nd and R.

after reading this statement I forgot all about the electrical symptoms. For some reason I assumed that it never made it to a shop, and the shop was told this over the phone. an e4od will get od with no wires hooked to it, and if the shop was told no 3-4 shift they would not be wrong in saying trans

After I reread the whole thing with my eyes open I saw that it went to a shop, and either they didnt drive the thing,or were trying to screw him, or didnt have a clue.

sorry for being a ****.

 

[OLDBULL8]

END OF THREAD.