Hello Chevrolet friends. I'm new here and I hope you can help me with my problem.

My 2007 Tahoe 5.3 is causing some problems, A rainy day, I was driving.
Suddenly the error message:
-Service Stabilitrac
-Service Service Traction Control
-Gearbox went into emergency mode (drive position display failed) and drives in last gear.

Later in the evening I noticed that the electric tailgate no longer opens and the parking assist dont work.

When reading out, I got various errors, including tailgate communication and U0101 TCM connection loss.

I have tried the following solution:

I have checked all the connectors on the underbody, they are clean and OK.
I checked the battery cables, cleaned them. Also the fuse connections for Batterie on the Body.
Ground connection cleaned from battery to engine, ground connection cleaned from engine to body (front).

Measured 60 ohms on the OBD socket between pins 4 and 16, so the resistance and GM-Lan are OK.

The Engine runs good, the lights work, car drives in limp mode.

Any solution or idea to show?

Regards Daniel

 

I know this isn't the same model, but you've checked some of the obvious trouble spots.
Frame to body ground straps need checked too.
Jump to 31 minutes, interesting possibility.

 

Thanks for reply!
Is there a scheme for all relevant Mass Points on Body?

Today i have tested the Power Connections from TCM.
Pin 32 Red/White has 12V, Pin 31 Pink has 12V.
Wake-Up Signal from BCM Pin 11 dark blue has 12V.
Ground Pin 49 Black/White has ground.

So it think the TCM becomes Power.

What else occurred to me: The door locks pops up and down, up and down really fast as the error beginns.

Regards and thanks

Daniel

 

There are over a dozen grounding points. Shop manual will list and show locations of every one of them. I use a subscription to alldatadiy.com for the vehicles in my fleet. It's an online real shop manual.

 

I work for a GM dealer. We have seen these issues when there is excessive resistance in the negative battery cable .

 

Hey Guys,

today i replaced the Battery with a brand new.
In addition, I exchanged the negative battery cable for a new one and renewed the ground connection G103.
The same error persists, gear indicator and tailgate don´t work, no communication with TCM.
Any additional ideas ?

Funnily enough, the split tailgate opens without any problems.

Yesterday have made an alldatadiy.com account, tomorrow i will check / replace all grounding points under the car.



Missing Gear Indicator

 

No Updates at this time.

Today i blanked all grounding points under the car (G100 / G101 / G102 / G103 / G110 / G300 / G400 / G401), renewed all sleeves, use contact spray and mounted it back.
The error persists further.

Since the gearbox limp mode together with the tailgate problem, I took a look at the tailgate control unit today.

Pin 3 has 12V.
Pin 4 has 12V.
Pin 6 has ground
Same as my TCM...Power but no work

It should actually work if it gets a signal.
When I press the button on the remote, the turn signal flashes and the controller clicks (a relay) but nothing happens.
If I press the button to close, nothing happens either.

I think some signal is missing, and my transmission control modul missed the same signal.

I don't know if I made a mistake when measuring, but in the tailgate module connector C3 E61 14 pin should be connected to pin 8 TN/BK circuit no. 5803 5V applied.
Here, however, I only measured 1V.

Can someone tell me where the electricity comes from? I don't quite get along with the cable plan

 

The 5v is called the reference voltage. Most control modules generate it for their sensors that they control.

 

News in the case: I found the bug!
A friend came today with the identical car and we put his transmission control unit in my car... and the error is gone.
My TCM is bad, now i will order a new controller.

The tailgate works again.

Thanks everyone for the help

Regards, Daniel