2006 M1114 Transmission Help

[ronbo-3]

Hello All,
I have a 2006 M1114 (4L80E - 4 Speed) that has been a project I started last winter. I have the vehicle running now and the next hurdle seems to be a transmission related issue. I am getting a code 83 and the trans light remains on after the truck has been started. The code 83 is for “Torque converter clutch (TCC PWM) solenoid circuit fault”.

What I have done: 1) Replaced TCC Solenoid 2) Added grounding harness 3) replaced speed sensor / crank sensor (was told if trans light stays on, likely because tcc does not know engine is running and this sensor tells TCM engine is running)

I ran through the 4L80 diagnostics and it led me to the following actions: Repair wire 924A and 290D/291A. I double checked and these wires and likely will tripple check after a few of your responses. Maybe I am not testing / checking them appropriately. I am out of state and will be home in a few days to continue diagnosing the issue with your helpful feedback. I do plan on replacing these wires when I return back home.

Driving: The vehicle will go in reverse and will shift through all gears briefly and then it sounds like it’s jumping down a gear which makes 4th gear obsolete and the engine rev’s will increase at this time.

I don’t want to take this to a trans shop as this is my project and learning process that will enable me to maintain and repair my vehicle when needed.

Thank You in advance gentlemen...

 

[Mogman]

The light will stay on if the TCM sees an issue with any of the solenoids, in your case it is the TCC solenoid.
Ignore the troubleshooting as it assumes you have a test harness. look at page 140 of the supplement if you don't have the supplement I will post it for you.
You will see 12V travels through wire 290 to pin E on the transmission connector if you do not have switched 12V at pin E then you need to find out why.

You likely do or you should be getting more than one code as the 1-2 and 2-3 shift solenoids would not be getting power as they are all powered off of pin E, connected inside the transmission.

You did wait and see that the 83 was the only code yes?

If you do then plug the harness into the trans and look at pin X on the unplugged TCM harness connector, you should see switched 12V there also, if not then the TCC solenoid is bad, the internal harness or harness connector/s are bad or wire 924 from the trans to the TCM connector is bad.

If you do not see 12V at pin X at the TCM connector ohm out the connection between pin X on the TCM connector and pin S on the trans connector.

Checking the voltages at the trans connector when connected would b a real PITA.

Was the trans connector wet with trans fluid?

Defective transmission internal harness is also fairly common.

 

[ronbo-3]

The light will stay on if the TCM sees an issue with any of the solenoids, in your case it is the TCC solenoid.
Ignore the troubleshooting as it assumes you have a test harness. look at page 140 of the supplement if you don't have the supplement I will post it for you.
You will see 12V travels through wire 290 to pin E on the transmission connector if you do not have switched 12V at pin E then you need to find out why.

You likely do or you should be getting more than one code as the 1-2 and 2-3 shift solenoids would not be getting power as they are all powered off of pin E, connected inside the transmission.

You did wait and see that the 83 was the only code yes?

If you do then plug the harness into the trans and look at pin X on the unplugged TCM harness connector, you should see switched 12V there also, if not then the TCC solenoid is bad, the internal harness or harness connector/s are bad or wire 924 from the trans to the TCM connector is bad.

If you do not see 12V at pin X at the TCM connector ohm out the connection between pin X on the TCM connector and pin S on the trans connector.

Checking the voltages at the trans connector when connected would b a real PITA.

Was the trans connector wet with trans fluid?

Defective transmission internal harness is also fairly common.

Thanks, will do these checks tomorrow or Monday. To answer your questions, code 83 is the only code and the trans connection did have a little fluid on it, maybe a drip or two.

Thanks again, will update post with results in a day or 2.

 

[ronbo-3]

The checks above have been completed and I do have the supplement doc mentioned above.

I do have 12 V going to pin E on the transmission harness connector when switched and also have 12 V to pin X on TCM harness connector. I have double checked and the only code received is 83, i let it cycle through a few times to ensure this is true. As mentioned above, i did have a drip or two on the trans harness connector to the J1 trans connector. What are my next diagnostic steps?

Also, when I dropped the trans pan to replace TCC solenoid & filter, i confirmed the solenoid connection is getting power or I ohm tested the line for continuity (can’t remember which one i did). I have already learned that i should have replaced the wire harness when in there, but didn’t know better at that time.

Any and all help is appreciated...

 

[Mogman]

If you are seeing 12V at pin X at the TCM connector then the circuit is complete.
What I would do to confirm is use my meter on the 10A scale and short pin X to ground simulating TCC lockup and measure the current.
I would expect to see about 1A, this is a modulated (PWM) solenoid so take the measurement rather quickly, to say don't hook the pin X to ground and go smoke a cigarette.

 

[Mogman]

If you do see around 1A then the circuit is OK, ether the harness/connector (pin X to B5) inside the TCM box are bad or the TCM has a problem.

 

[ronbo-3]

If you are seeing 12V at pin X at the TCM connector then the circuit is complete.
What I would do to confirm is use my meter on the 10A scale and short pin X to ground simulating TCC lockup and measure the current.
I would expect to see about 1A, this is a modulated (PWM) solenoid so take the measurement rather quickly, to say don't hook the pin X to ground and go smoke a cigarette.

I don’t see any amps, but i’m not sure i’m testing correctly.

What I did: I jumped X to slot a (tcm J1 ground & also grounded to bolt in another test) with a short wire, on that wire i have a spot for my + side of meter and put - on a good bolt ground connection. I turned switch to run and am expecting a jump to ~ 1A for a short time then change to an unknown to me number. If this is the correct process, I do NOT see any amps on meter. After this test, I did a test on X again and confirmed 12V and about 5A if I am not grounding X out. Please confirm my test was done correctly, thanks...

 

[Mogman]

You connect one lead of your meter to pin X, the other lead to ground.
Meters require you to plug one lead into a different place on the meter to read amps and of course a different meter switch position, you may need to read the instructions for your meter.

 

[ronbo-3]

Thanks again, after double checking my work, I realize my multimeter has internal fuses that i never changed in it’s life (attained meter when i was still jumping out of helicopters in the 90’s). The fuse failed the test, will replace and report back. Thanks again...

btw: My meter has 10A and 300mA settings

 

[Mogman]

Thanks again, after double checking my work, I realize my multimeter has internal fuses that i never changed in it’s life (attained meter when i was still jumping out of helicopters in the 90’s). The fuse failed the test, will replace and report back. Thanks again...

btw: My meter has 10A and 300mA settings

It is extremely easy to forget to move the lead back to "volts" so the next time you go to check volts the fuse pops, been there done that several times..

 

[Mogman]

I set up and measured just over 1A (1.1 actually) from X to ground.

 

[ronbo-3]

I replaced the fuses and have pretty much exactly 1A….I will check the harness/connector (pin X to B5) next, will report back soon.

 

[Mogman]

I replaced the fuses and have pretty much exactly 1A….I will check the harness/connector (pin X to B5) next, will report back soon.

While you are in there look for signs of water intrusion.

 

[ronbo-3]

Harness / connector seems good and is getting 12v to pin B5. Last night I took the TCM apart to visually check it out and see if there is any obvious issues and didn’t find any. The TCM was dry and packed well with foam surrounding so I know it wasn’t bouncing around, it looks like the TCM will need to be replaced. I want to thank you for the continuous help and patients through this diagnostic process, next time please lead me to a blown sensor or something cheap…lol

 

[ronbo-3]

I took the TCM apart, and i don’t see any obvious repairable issues. I believe the failure on the board is the TLE 6220 GP E-PROM in which i traced the issue to (B5 pin). I can see on the back side of the board there is a brown tint color around the back side of the suspected bad EPROM location but as you see there is no discoloration exactly behind it (you can see a green rectangle in middle of brown area). Can the EPROM be replaced or should the TCM entirely be replaced? I am not sure if I replace EPROM it would work as i believe it would have to have to have the correct drivers / software to communicate to the specific TCM. Do you have any recommendation on sourcing the parts and would you recommend new or rebuilt?

One more question - On the TCM, there are two TLE6220 GP EPROM’s, could I move the assumed good one and replace the bad one? This should minimally turn the trans light off upon start if I am correct. I haven’t looked at what the good EPROM is used for, just had a quick thought to double check diagnostics.

Thanks

 

[Mogman]

There is nothing serviceable on that TCM.
You can replace that one with the older style that requires a plug in EPROM, the EPROM can be bought at Eastern, it is the cheapest way to go as the rebuilt TCMs are around $200

Eastern Surplus

Fortunately you have a turbo truck so it is the cheaper one, I don't have the TCM part number handy, maybe someone will jump in here, I will do some research also.
One thing you should do now is put it all back together and make sure you are still getting a 83 code.

 

[Mogman]

I think one of the numbers is 88999230

 

[ronbo-3]

There is nothing serviceable on that TCM.
You can replace that one with the older style that requires a plug in EPROM, the EPROM can be bought at Eastern, it is the cheapest way to go as the rebuilt TCMs are around $200

Eastern Surplus

Fortunately you have a turbo truck so it is the cheaper one, I don't have the TCM part number handy, maybe someone will jump in here, I will do some research also.
One thing you should do now is put it all back together and make sure you are still getting a 83 code.

Still an 83 code - I can see a discoloration on one of the small arms coming down from the EPROM, likely the root cause. $200 for a refurbished one sounds like a deal. i’ve been seeing new ones for around $1,200 at reputable dealers and $700 at others who don’t necessarily have the best reviewed on here. I will be searching for a refurbished TCM, hopefully that will resolve the issues. If I knew 100% that it was the TCM, I would just buy a new one. Wish i knew someone local here to pop theirs in to check.

 

[Mogman]

If you have enough patience I can send you one to test.
You pay both ways.

 

[Mogman]

Although it does appear you have a bad TCM as the TCC circuit is complete and tests good.