Need an auto transmission expert....E4OD

[tgreening]

1992 E350 ambo conversion. Just rebuilt.

I parked it this past friday and everything was working perfect. Fired it up sunday and before I got out of my driveway I could tell something wasnt quite right. ABS light is on constant. Speedometer waves around like a confederate flag and sometimes drops right to zero. When this happens the transmission starts acting all wonky. Makes what seems like random up/down shifts. Sometimes feels like it drops into neutral. When the speedo is acting normal, tranny is fine. As soon as it starts waving around the tranny gets funky.

I checked all the plugs on the tranny to make sure they were seated. I checked the ABS plug back on the diff. There is no VSS. Beyond this I am at a loss as to where to look or even really begin. Any informed insight is MORE than welcome.

 

[Bbasso]

Check the grounding cables.
A bad ground can cause some odd problems.

 

[Bikersmurf]

Sorry, not an expert. From what I've read your speed sensor is likely on your Diff. Could it's input also be related to the ABS?

I think your tranny may be fine... But with computers, garbage in = garbage out. If the speed sensor is faulty, the tranny may have no idea what it should do.

 

[jkam]

Sounds like the speed sensor to me. It is in the diff and easy to replace. You can get one at most auto parts places for less than $40.

That said, the E4OD could be part of the problem, especially if it has about 100,000 miles on it. They are known to have the front pump fail and cause problems.

Also, the ABS light on my 96 is always on as well. The sensor in the rear has been replaced and it still did't fix the issue for long. I just ignore it now as the brakes work fine.

 

[tgreening]

I intend to start with the ABS/Speed sensor in the rear diff. It's cheap and if nothing else will give me a part with a known history. As far as ABS function, I believe there is that part, plus up on the drivers side frame rail there is a pressure switch in the brake line that I'm pretty sure ties into that ABS circuit as well. I checked the fuses and they're both good. Pretty sure that pressure switch has been replaced but that doesn't mean it didn't go bad. I know if it goes you'll get that ABS light and the cruise will cease to function. Wiring seems to be good from the rear diff forward. Seems.

Anyway, ABS sensor first, then that switch. After that I'm head scratching. I know there is a component (nomenclature escapes me) up in the gauge cluster that deciphers crap coming from various sensors and then sends that info on to the transmission control unit, but I have no idea how to go about testing its function and I'd rather not just toss that particular part at the problem. My willingness to do shotgun maintenance goes only so far.

 

[tgreening]

Also, the ABS light on my 96 is always on as well. The sensor in the rear has been replaced and it still did't fix the issue for long. I just ignore it now as the brakes work fine.

You might want to check the frame rail for that pressure switch I mentioned. Couple wires coming out of it, probably a blade fuse holder in the circuit right there. Think it might be screwed into the diverter valve but can't remember that for sure. Odds are it takes care of your ABS light, and if you have cruise that isn't working probably takes care of that as well.

I've had that same problem and failed part on 3 different Fords now. This '92 van, a 2001 F250, and a 2000 Excursion. Same part, same problem across the board.

 

[jkam]

The system has been checked and it seems that the ABS brain would need to be changed and I'm unwilling to spend that kind of money when the brakes work fine.
There was recall on the switch on the brake master cylinder, that was done and it still trips the ABS light when I step on the peddle.
Been driving it this way for 7 years now with no other brake issues.

 

[tgreening]

It seems as if the ABS sensor did the trick. Seems.

Speedo settled down, ABS light went out, and the tranny is back to normal. So unless it's an electrical gremlin that took today off it appears I'm back on the road for a whopping $15 dollars and about 20 minutes total putzing about.

Score one for the home boy.

 

[frig84]

The rear ABS sensor is also used as the output shaft speed sensor for the trans. With it acting up, the PCM(ecu) had no way of knowing if the trans was working properly, or even what gear it was actually in.

Sent from my SCH-I545 using Tapatalk

 

[AFBronco235]

It seems as if the ABS sensor did the trick. Seems.

Speedo settled down, ABS light went out, and the tranny is back to normal. So unless it's an electrical gremlin that took today off it appears I'm back on the road for a whopping $15 dollars and about 20 minutes total putzing about.

Score one for the home boy.

Good to know you got it worked out. As a follow up, you may want to pull the fill plug on the diff and see if there are any metal shavings on the magnet. There will always be some, but a lot could indicate grinding and the shaving could have been the original cause for the failure of the sensor. Just something to look into so you're not scratching your head later down the road if it goes bad again.