90 AOD limp mode

[DWilliamA]

limp mode when cold - but comes out when engine (or tranny) warms up after 10 minutes or so - every thing drives ok, no lurching or harsh shifting.

note... driving it a few days ago started in 1st gear at stop light after coming out of store and engine was relatively cold... and forgot to shift out of 1st, so it was revving pretty good and then it like popped and released.. continued to drive after that not in limp mode... so for next few days back to the normal limp when cold - ok when warm... like it never happened.

history if it matters - wire harness to the transmission passenger side got melted and fried up pretty good from my exhaust. I had thermactor issues and a pipe near the cat convert was broke... so I fixed the wire harness, and the exhaust stuff... put a heat shield and limp mode went away. last week it started to limp again (per above description) and I discovered a couple wires had melted again.. my heat shield wasn't working so great.. exhaust is probably still hot too... fixed the 2 wires and its still limps now, and there was that pop release thing, not good I assume.

just tested obd1 codes and getting in the order tested, i.e., 93 was last

56 transmission oil temperature sensor fault
91 shift solenoid 1 circuit failure
92 shift solenoid 2 circuit failure
94 converter clutch control circuit failure
99 Electronic Pressure Control circuit failure
93 coast clutch circuit failure

Is a new solenoid going to fix all this, or is maybe the tranny control module a part of this considering the fried wire situation.. or both... ???

 

[Tiha]

Someone else can answer this better. I believe the TCM is part of the ECM.

Pretty odd for all of those to fail at once. Would think it is still a wiring issue someplace. If you haven't pulled the pan I would imagine there could be heat damage inside? No idea.

 

[L\Bronco]

limp mode when cold - but comes out when engine (or tranny) warms up after 10 minutes or so - every thing drives ok, no lurching or harsh shifting.

note... driving it a few days ago started in 1st gear at stop light after coming out of store and engine was relatively cold... and forgot to shift out of 1st, so it was revving pretty good and then it like popped and released.. continued to drive after that not in limp mode... so for next few days back to the normal limp when cold - ok when warm... like it never happened.

history if it matters - wire harness to the transmission passenger side got melted and fried up pretty good from my exhaust. I had thermactor issues and a pipe near the cat convert was broke... so I fixed the wire harness, and the exhaust stuff... put a heat shield and limp mode went away. last week it started to limp again (per above description) and I discovered a couple wires had melted again.. my heat shield wasn't working so great.. exhaust is probably still hot too... fixed the 2 wires and its still limps now, and there was that pop release thing, not good I assume.

just tested obd1 codes and getting in the order tested, i.e., 93 was last

56 transmission oil temperature sensor fault
91 shift solenoid 1 circuit failure
92 shift solenoid 2 circuit failure
94 converter clutch control circuit failure
99 Electronic Pressure Control circuit failure
93 coast clutch circuit failure

Is a new solenoid going to fix all this, or is maybe the tranny control module a part of this considering the fried wire situation.. or both... ???

In 1990, the electronic trans will be E4OD. Those are all circuit failure codes, Check the harness where it was repaired really close. Verify the 2 red wires have 12v with the key in the run position and the black with white stripe has .5-5V with the key on.
I'm with Tiha, its unlikely that all of that failed at once.
Given the history, I would suspect the wiring.
And with that many codes, look closely at the power supplies. Make sure the connector at the trans is seated properly and there is no fluid inside the connector on the trans.
Hope that helps
Cheers

 

[Motech]

@Tiha is correct. All Ford EEC systems incorporate engine and transmission controls in one module. That's why it's referred to as Powertrain Control Module (PCM) and not Engine Control (ECM).

With all the damage and mods to these critical control circuits that live in such a hostile environment, I agree with both that your harness repairs must be top priority.

For long term reliability, it's probably a good idea to source an entire ATC sub-harness to replace it with.

 

[DWilliamA]

I haven't checked volts yet... but I did check all wires and harness etc visually ... everything looks good ... the truck right now when cold is in limp mode with no OD flashing... OD light doesn't work at all at the moment... not sure if it has to be in gear to work, so I put it in gear... no OD light function at all.

yesterday while limping home... it 5 or 6 times starting flashing the OD light,.. for 5 minutes, then stop, it drove differently with and without the OD light blinking .. when blinking I had real bad hesitation issues could barely press on gas at all... to limp out of an intersection I put it in 4 low and literally idled out... once the OD light stopped flashing I could drive a little easier, but I always had to go easy at slower speeds but it would lightly cruse along back roads at 35 mph... Ok in town at stop lights going really easy too .. but once the OD started blinking I had to shift in 4 low and drive it super easy .. then the OD would stop blinking and I could shift out of 4 low... the hesitation symptom was the classic uh uh uh uh uh uh uh uh uh in gear.. and with enough throttle in nuetral would clear out into higher revs... don't know if any of this has a clue in it...

question... if I replace the solenoid pack, which seems relatively easy to do ... will all those code related issues be fixed, assuming its the solenoid pack of course... or will I need to rebuild the tranny in part or whole ?

meantime I will check Volts too, later tonight

 

[DWilliamA]

@Tiha is correct. All Ford EEC systems incorporate engine and transmission controls in one module. That's why it's referred to as Powertrain Control Module (PCM) and not Engine Control (ECM).

With all the damage and mods to these critical control circuits that live in such a hostile environment, I agree with both that your harness repairs must be top priority.

For long term reliability, it's probably a good idea to source an entire ATC sub-harness to replace it with.

I was looking on ebay for a harness... no luck... it appears 89-92 f150-350 2/4wd and econoline same years will work...

 

[DWilliamA]

I was looking on ebay for a harness... no luck... it appears 89-92 f150-350 2/4wd and econoline same years will work...

regarding wire harness... will the MSD atomic TCU from summit racing work... thinking not...

 

[L\Bronco]

yesterday while limping home... it 5 or 6 times starting flashing the OD light,.. for 5 minutes, then stop, it drove differently with and without the OD light blinking .. when blinking I had real bad hesitation issues could barely press on gas at all... to limp out of an intersection I put it in 4 low and literally idled out... once the OD light stopped flashing I could drive a little easier, but I always had to go easy at slower speeds but it would lightly cruse along back roads at 35 mph... Ok in town at stop lights going really easy too .. but once the OD started blinking I had to shift in 4 low and drive it super easy .. then the OD would stop blinking and I could shift out of 4 low... the hesitation symptom was the classic uh uh uh uh uh uh uh uh uh in gear.. and with enough throttle in nuetral would clear out into higher revs... don't know if any of this has a clue in it...

When a code 99 sets, the PCM has no control of the line pressure, to protect the transmission from damage, half of the injectors get shutdown to limit power.
With all the DTCs you have, it looks like a loss of power to the solenoid body not the body itself. Plus the running issue is a reaction to the fault, not the cause of the fault.
Stay on the wiring track.
Cheers

 

[DWilliamA]

Thx

 

[Motech]

regarding wire harness... will the MSD atomic TCU from summit racing work... thinking not...

I wouldn't trust it. The MSD atomic stuff that I have installed has been real disappointing.

 

[DWilliamA]

Anyone have the exact make model year cross references for the transmission solenoid wire harness for a 1990 351w 4wd E40D .. ? I have heard here and there that 89-92 F150-350, Bronco and Econolines may work with no mention that it has to be exactly a 4wd harness or exactly 351 only... make it sound like they are interchangeable to some degree... then...

.... I when junk yarding... found a couple harnesses that seemed correct on both ends, but none of them have the 4 wires that go to the TCM pictured below.. what is strange about the TCM wires they go through a frame hole that is too small to get the plug end through, the TCM is mounted directly across from the main harness grey plug on the other side of the frame rail ... so the wires had to be added in to the TCM plug on the other side of the rail ?? ... pay no attention to my franken-wire ... those 4 original wires fell on to the exhaust and burnt so I had to replace 1 of the wires for sure.. but the replacement plug made me splice into all of them .. the wire mesh and aluminum tape act as both heat shield and bendable shape holder to help keep the wires up and away from the exhaust for the time being ... none of the EFI trucks i saw at the junk yard had TCM's on them, or wires for a TCM .. or the TCM was located some place else but I never saw one.

also, on close examination.. my harness, assuming my repairs are solid (now that its out I am going to solder), appears to be in good shape... the original harness plug (grey plug shown) was all deformed and melted ... So I think my problem with limp mode is the other end of the plug in the Tranny, it looks ok what little I can see but I am thinking it may be messed up ... Is this plug in the tranny replaceable or do I need a whole new solenoid? If I am going to drop the pan and remove Solenoid to replace the plug part, considering the harsh treatment and mileage on this tranny I might just put in a new Solenoid in it.. which begs the next question... any good sources for solenoids

summary
help with identifying the correct harness I need Bronco Centurion 1990 351w 4wd E40D
comments about the TCM wire/plug scenario
solenoid plug replacement vs new solenoid with recommended sources

 

[Motech]

That BANKS TCM200 is an obsolete, aftermarket piggyback transmission controller. It modifies factory AT controls to alter shift solenoid commands for firmer, extended shifting.

I suspect the breakout wires in the second photo are spliced onto factory control circuits for the BANKS processor.

This definitely reinforces replacement harness option.

 

[Motech]

Here is a Ford TSB that may be useful in confirming your circuit connections.

 

[Motech]

1992-1996 FORD F150 97 F250 F350 BRONCO E4OD TRANSMISSION WIRING HARNESS OEM | eBay

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[DWilliamA]

1992-1996 FORD F150 97 F250 F350 BRONCO E4OD TRANSMISSION WIRING HARNESS OEM | eBay

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my harness has 3 connectors at the engine bay end... neither of these will work...

 

[DWilliamA]

Here is a Ford TSB that may be useful in confirming your circuit connections.

thank you .. I have this, used it when I spliced in my replacement plug

 

[DWilliamA]

That BANKS TCM200 is an obsolete, aftermarket piggyback transmission controller. It modifies factory AT controls to alter shift solenoid commands for firmer, extended shifting.

I suspect the breakout wires in the second photo are spliced onto factory control circuits for the BANKS processor.

This definitely reinforces replacement harness option.

ok ... Banks is aftermarket ...btw.. it was the wires to the Banks that burnt up.... that mean I don't have to have it and can just use a regular harness and omit the Banks??? if I want it... I need to replicate the way they spliced the banks into the main harness... 2 of the wires are spliced into wires that continue to the harness plug... 2 of the wires from main harness go directly to the banks and by pass the harness plug.. seems logical at some level.. don't have a schematic for that .. I copy my harness easy enough.

my wire harness actually looks good asuming my splice work is good.... the main plug at the tranny seems casual. its pretty easy to get off and on.. .I suspect my solenoid plug is buggered up.

 

[DWilliamA]

regarding keeping the Banks or not... I have 33x15 tires on my truck... they definitely make the truck feel like its driving heavy wheel tire wise ... Banks good or bad in this regard... and yes the 33" fit, I had to move the front bumper foward an inch and it does rub inside on sharp turns, but its such a long truck I don't cherish a sharp turning radius anyway and what little radius I lost wasn't much from an already crummy turning radius..

 

[DWilliamA]

ok ... Banks is aftermarket ...btw.. it was the wires to the Banks that burnt up.... that mean I don't have to have it and can just use a regular harness and omit the Banks??? if I want it... I need to replicate the way they spliced the banks into the main harness... 2 of the wires are spliced into wires that continue to the harness plug... 2 of the wires from main harness go directly to the banks and by pass the harness plug.. seems logical at some level.. don't have a schematic for that .. I copy my harness easy enough.

my wire harness actually looks good asuming my splice work is good.... the main plug at the tranny seems casual. its pretty easy to get off and on.. .I suspect my solenoid plug is buggered up.

Owners Manuals

Banks Power Owners Manuals provide you with important, product specific information regarding the installation and use of your product. Look below to find

official.bankspower.com

found this page... has everything except 5.8 gas stuff...

 

[DWilliamA]

Here is a Ford TSB that may be useful in confirming your circuit connections.

this is the other end of the harness