P0740 and P2762

[stkelly]

My 08 Moutaineer with 140K miles all of a sudden got real sluggish when I tried to accelerate from a stop light. The check engine and wrench light came on. Before this the truck drove perfectly fine, no indication there was any transmission issues.

I checked the codes, P0740 (torque converter clutch circuit) is set and P2762 (torque converter clutch pressure control solenoid) is pending.

When I shift from P to D or R there's a clunk from the transmission and the whole car lurches.

I'm going to put the truck on ramps and remove the transmission pan and see if there's any metal chunks.

I changed my radiator in March, about 10,000 miles ago. I approximated the additional fluid based on what I collected out of the old radiator and what dripped from the disconnected lines. I figure I would have had an issue sooner if I over or under filled the transmission. Of course, the transmission dip stick is broken, I have a new one on order from the dealer.

Any ideas on what could be going on? Maybe the solenoid pack needs to be replaced?

Thanks in advance!!

 

[stkelly]

I tried to reset the codes, P0740 comes back immediately. I don't even need to start the vehicle for the code to come back. This points to something electrical. I ohmed out the transmission fuse and it was fine. P2762 will sometimes come back immediately as well.

I checked the connection to the transmission and it looks fine. The wrap going to the transmission is disintegrating, but the wires inside the wrap look fine.

Any suggestions?

Thanks!

 

[stkelly]

Any chance anyone has the pin out for the transmission to ECM/PCM wire harness? I traced as much of the cable as I could and didn't find any breaks or rubs in the wire itself. I want to ohm out each wire but can't find where the wires connect to the computer. There are so many wires and close colors that it's pretty hard to match.

Thanks!

 

[08EddieCA]

I'm not too knowledgeable with transmissions. However, in March when you installed the new radiator did you also service your transmission? My trans is very sensitive to correct fluid levels.

What transmission do you have?

 

[stkelly]

I'm not too knowledgeable with transmissions. However, in March when you installed the new radiator did you also service your transmission? My trans is very sensitive to correct fluid levels.

What transmission do you have?

I have the 6R60 transmission. I didn't fully service it when I replaced the radiator. When I pulled the radiator I dumped all the fluid in the radiator and let the trans lines drip into an empty container. I put a little bit more new Mercon SP fluid than what I collected from the container back into the transmission.

My dealer should have the new dipstick in sometime today. I'm going to double check the levels once I have the stick. I put a piece of small plastic into the hole and can see that the fluid is brown, it smells a little less pungent than the new Mercon SP fluid I have left over. It doesn't smell burnt.

Thanks for the help.

 

[stkelly]

I took the truck to an independent transmission shop. They said the mechatronic unit is bad. $2,100 to replace the unit ~$1,600 is the part alone (valve body with mechatronic). I asked about using an eBay remanufactured one since they're $300. He said he's had terrible luck with them and won't put them in anymore.

Has anyone had luck with remanufactured valve body/mechatronic units? The replacement looks easy enough, the problem is programming the TCM to the car.

 

[08EddieCA]

For that price I might see what the stealer charges to diagnose - not disassemble. In the past I've tried adding a quart of trans oil just in the off chance it was low.

Second item I might try is let your battery remain unconnected overnight if you don't have a jumper to drain the electronics. Sometimes this helps.

 

[Explorer_PL]

I have an 06 with 6R60 and replaced the mechatronic with an ebay unit.
I was getting communication error with the TCM and the dealer diagnosed mine to have defective TCM. They said, it's probably cracked from the heat. Since they can't get just the TCM, they were trying to sell me the whole unit (valve body + TCM = Mechatronic) for about 2600. SInce the car already had 200k miles, they said, they recommend new tranny for 5000, later they dropped it to 4000.
I did not go for that. I ordered a new valve body from eBay for $ 500. That did not fix the issue, the car would throw the errors and go into a limp mode. So I contacted the seller, he put me trough with their tech dept. The mechanic told me to check the coils, and I said thank you (thinking what is the guy talking about), my coils are new (Accel yellow coils), and I told them to send me another valve body. No problem, they did trusting me to send their first one back (I already sent my OEM core). I got another valve body, put it in, still same issue. Then I found an article online sttaing that bad coils create some type of interferance with teh TCM harness running close to them.

Got new coils and the problem never came back.

But....
To answer your question, I have about 50k on the ebay mechatronic unit, 250k on original tranny and it drives same like 10 years ago.

http://www.explorerforum.com/forums...c-replacement-saga-continues-pictures.436342/

 

[stkelly]

I had all sorts of strange throttle body control issues a while back when I had the yellow Accel coils. I ended up removing the Accel coils and putting back the original Motorcraft black coils with new springs and insulators. I haven't had the throttle body control issues since. However, I'm not 100% sure the TB issues were due to the coils. I was desperate to solve my random turn off/throttle body codes that I also wrapped the harnesses near the coils with foil tape and cleaned the contracts to the TPS sensor at the same time. So any one of those items could have fixed the issue.

The truck is at the shop now so it's harder for me to try and swap the coils. I may run up there and see if swapping the left and right coils help. However, the P0740 gets thrown the moment I turn the key to the on position. The truck doesn't even need to be started. I also tried disconnecting the battery and doing the jumper to clear ECM/PCM. The moment I turned the key to the on position the wrench came on.

Bummed I didn't just swap the TCM/Valve body. At $300 bucks it's worth the try, I figured the dealer wouldn't do the reprogram to the TCM.

 

[stkelly]

But....
To answer your question, I have about 50k on the ebay mechatronic unit, 250k on original tranny and it drives same like 10 years ago.

http://www.explorerforum.com/forums...c-replacement-saga-continues-pictures.436342/

Explorer_PL, thanks for the info. I requested the shop wait until I get the part on eBay. 1600 vs 300 I can go through 5 bad eBay ones. Even worse, after calling my Ford dealer I found out what you buy from Ford is remanufactured anyway. I'd bet Ford doesn't actually do the work, and probably gets them from the same place the eBay seller does!

Thanks again.

 

[Explorer_PL]

In my case both rebuilt mechatronics were good, I had the other problem.

 

[stkelly]

Just to follow up on this issue, a new mechatronic unit fixed this issue. I ended up ordering one from eBay for $300 and had the transmission shop install and reprogram the unit. The car drives perfectly fine, and no more codes at this point. Luckily, there was no damage to the transmission and there was very little metal fragments in the old fluid.

Thanks again for all of the help!