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Discussion Starter #1
Hello!

It seems like i have an electrical issue on my 1997 Suburban.

Problem:
Truck runs in reverse, but will just go a few metres forward. I believe its an electrical issue since the tcc solenoid is constant on.

I have diagnosed as much i can and also replaced the tcc solenoid, B shifting solenoid, speed sensor on tranny and transfer case and brake switch. Transfer is a 4L80E freshly rebuilt.
I have also checked and added ground everywhere.

When im using my OBD tool i have 2 parameters pending while idling:
TCC brake switch: pendling from closed to N/A.
Cruise: pendling from Disabled to N/A

I also have a suspect loose pink cable hanging from the dash. I cant find the electrical scheme for my model so hard to tell what it does.


I cant find any workshop nearby in Sweden who is willing to work on my truck...

Im thankfull for any ideas how to troubleshoot this... truck havnt been running for 2 years cause of this :( .

( Im from Sweden so i hope u have some understanding bout my bad typing. )
 

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Make sure the transmission fluid level is correct.
Unplug the large round electrical connector on the drivers side of the transmission, then drive it.
It will be stuck in 2nd gear only.
If it still will not move then the problem is mechanical.
If it drives ok (will only be in 2nd gear) then the problem is probably electrical.
All the wiring diagrams for your Burb are in the FAQS sticky, section 8 in the 97 service manual.
 
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Discussion Starter #3
Make sure the transmission fluid level is correct.
Unplug the large round electrical connector on the drivers side of the transmission, then drive it.
It will be stuck in 2nd gear only.
If it still will not move then the problem is mechanical.
If it drives ok (will only be in 2nd gear) then the problem is probably electrical.
All the wiring diagrams for your Burb are in the FAQS sticky, section 8 in the 97 service manual.
Thanks!!!
I Will try this tomorrow :) .
 

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Discussion Starter #6
Make sure the transmission fluid level is correct.
Unplug the large round electrical connector on the drivers side of the transmission, then drive it.
It will be stuck in 2nd gear only.
If it still will not move then the problem is mechanical.
If it drives ok (will only be in 2nd gear) then the problem is probably electrical.
All the wiring diagrams for your Burb are in the FAQS sticky, section 8 in the 97 service manual.
So i did as u said... it wont move even if the cable is unplugged..

It wont move is false cause it will go a few metres.. and even further in reverse..

Wierd thing is.. if i unplug the tcc solenoid inside the pan. Truck runs great :( .
 

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1995 Chevrolet Silverado Z71 6.5 TD
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189 Posts
Hello!

It seems like i have an electrical issue on my 1997 Suburban.

Problem:
Truck runs in reverse, but will just go a few metres forward. I believe its an electrical issue since the tcc solenoid is constant on.

I have diagnosed as much i can and also replaced the tcc solenoid, B shifting solenoid, speed sensor on tranny and transfer case and brake switch. Transfer is a 4L80E freshly rebuilt.
I have also checked and added ground everywhere.

When im using my OBD tool i have 2 parameters pending while idling:
TCC brake switch: pendling from closed to N/A.
Cruise: pendling from Disabled to N/A

I also have a suspect loose pink cable hanging from the dash. I cant find the electrical scheme for my model so hard to tell what it does.


I cant find any workshop nearby in Sweden who is willing to work on my truck...

Im thankfull for any ideas how to troubleshoot this... truck havnt been running for 2 years cause of this :( .

( Im from Sweden so i hope u have some understanding bout my bad typing. )
had a similar problem on my 1999 Yukon Denali it was a 5.7 though. It started out not shifting into OD for a few miles and eventually only reverse would work. The prognosis was the sun gear had failed and had to either get it rebuilt or a GM reman that had all the updates that had been rolled out for the 4L80E. that's my two cents...Do the GM REMAN if your going to keep the TRUCK
 

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Discussion Starter #8
had a similar problem on my 1999 Yukon Denali it was a 5.7 though. It started out not shifting into OD for a few miles and eventually only reverse would work. The prognosis was the sun gear had failed and had to either get it rebuilt or a GM reman that had all the updates that had been rolled out for the 4L80E. that's my two cents...Do the GM REMAN if your going to keep the TRUCK
Thanks for ur reply, but my transmission is freshly rebuilt.
 
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