Trans wiring harness issues. 4x4, trans malfunction, DBC, DSC, AWD, brake light on

[brokenbim]

I get a 4x4, trans malfunction, DSC, DBC, AWD, brake, and sometimes no lights on the automatic transmission shifter at all... which then means you have a non starting car. At first, if i crawled under the car and wiggled the wires of the plug at the transmission's mechantronic unit sleeve, it would work again... for awhile.

Here are some old codes from Aug of this year that might help? (i did change all my lights at this point, which i think is the reason for those codes) Recent codes are in post #7-8








While I was changing the trans fluid and mechatronic sleeve, I noticed the 90 degree Plastic cap, (that the wires run through into the twist lock of the mechantronic sleeve) was opened up and sitting on there loosely. So I proceeded to stuff the wires back in there properly and thats when the lights started. I think. So i left them in there loose again.

Does this look like the start of a failing transmission ecu?

[crystalworks]

I don't have experience with your problem, but have plenty with the transmission, EGS, and mechatronic unit. If you notice damage on your harness, replacing it is not a bad idea, if not time consuming.

But, there is absolutely a chance the pins on the mechatronic itself are damaged. Or something inside the trans. I'd drop the valve body and inspect the harness internally to check for damage and continuity. Another possibility is that the seal got torn and trans fluid is intruding into the mechatronic sleeve... but I think you'd notice that at the plug end of your harness.

[brokenbim]

Or maybe test the plug, or the wires to the plug, with a multimeter or something?

[crystalworks]

Originally Posted by brokenbim

Or maybe test the plug, or the wires to the plug, with a multimeter or something?

Yes, you could check continuity between the plug and the DDE harness. If all terminals check out, you can cross it off as a culprit.

Do you have any fluid contamination in the harness or plug? I've seen that cause symptoms similar to yours.

I reread your first post and saw you did not drop your valve body. No need to check the internal harness.

[brokenbim]

I was just going to update this but you beat me to it. I now know that the biggest red wire was broken proven by jumping ohms. I also stuck a pin through the plug of the same red wire, to tighten it up on the mechantronic.

Seems to keep the lights off so far...


But no crystalworks, i did not drop valve body, but the gorilla before me might have. The fluid wasnt too bad looking or smelling. Thanks for the help though.

[crystalworks]

No problem. Glad you sorted it out. Tracing electrical problems can be a bear. I don't know how that damage would occurred other than maybe a bad splice from the factory that came loose when the mechatronic sleeve was changed.

[brokenbim]

Im back...

I don't even know where to start. I am getting "shift lever malfunction" when the transmission gets up to 3rd and 4th gear. I do have a new battery registered and coded to 90ah agm. I also changed all the fluids in the front, rear, transfer case, and trans. I thought I was leaking trans fluid through the mechatronic sleeve causing the codes, so I dropped the valve body and changed the mechantronic sleeve, along with all the seals under the valve body.

I also recently got codes for lean, which after smoke test, was leaking air from the disa and the valvetronic unit. Valve cover also semi newly replaced. I also got a new misfire on cylinder 1, moved coil to two, got misfire code on two. Changed the coil yesterday. Not sure if faulty coil in cylinder 1 is any clue to this?

I also now have a new loud clicking noise coming from the back left tire. It seems to quite some after picking up speed. (Driving in circles does not make the noise.)

So I guess my biggest concern is the "shift lever malfunction" and the clicking... IDK at all. All this seemingly happened at once, maybe from the cold?

Never did "check continuity between the plug and the DDE harness" as stated by crystalworks.

Here are the codes from my last few scans.

[brokenbim]

This is a OBDfusion scan from Saturday night after a five minute drive.
2Diagnostic Report 2021-12-17 171644.html.pdf

So the next day i drove it no faster than 50mph with no lights coming on. Then I was cruising up my street at about 25-30mph when all the lights came back on...





Let me add again that, all the above codes in thread title, used to go out for a little while after wiggling the wires of the plug at the transmission's mechantronic unit sleeve. Clue?

*Also when i hold the rpm up past 2000 for 30 seconds, the engine cuts out and has a malfunction warning on the idrive.

Should i drop the valve body again and inspect the harness internally to check for damage and continuity, as mentioned above? I need to do something... This really sucks.

[ard]

Geez. 2.5 MONTHS.



Sorry man, sucks.

[brokenbim]

Originally Posted by ard

Geez. 2.5 MONTHS.



Sorry man, sucks.

Instead of making a new thread, i resurrected my old one.The codes were going away by wiggling the wires at the mechatronic plug. I just started getting non-stop codes two weeks ago. I didnt have the misfires when i first made this thread. Just hoping I dont need a mechatronic unit...