I've got a thread going in electrical (No Start Grounds).
I've started this thread since I narrowed the problem down to the TCM.
I had a "no crank" condition:
U1000 U1016
OBDLink ScanXL would not communicate with ECM or TCM
It would communicate with EBCM and Restraint Modules which gave me the codes.
Key in ACC no line under PRN321 showing what gear I was in and the cluster would fade in and out sometimes go blank
Key in Run VATS light stayed on fuel read empty fuel low light on and more.....
Key in Start nothing no solinoid click, nothing
I took the TCM out of it's case and set it aside so I could better check the ECM wiring. After check I reconnected the battery and the truck was back to normal.
After a couple of missteps I realized that it was the TCM case grounding that fixed the problem.
I installed the TCM back in the case and ran a jumper wire from a ground to the TCM case. All seems normal with the jumper connected.
Can I damage the TCM with this external jumper?
I see that the TCM grounds are zone 4, right rear engine block, in the GM Upfitter Manual.
Are there other grounds I should check?
I've started this thread since I narrowed the problem down to the TCM.
I had a "no crank" condition:
U1000 U1016
OBDLink ScanXL would not communicate with ECM or TCM
It would communicate with EBCM and Restraint Modules which gave me the codes.
Key in ACC no line under PRN321 showing what gear I was in and the cluster would fade in and out sometimes go blank
Key in Run VATS light stayed on fuel read empty fuel low light on and more.....
Key in Start nothing no solinoid click, nothing
I took the TCM out of it's case and set it aside so I could better check the ECM wiring. After check I reconnected the battery and the truck was back to normal.
After a couple of missteps I realized that it was the TCM case grounding that fixed the problem.
I installed the TCM back in the case and ran a jumper wire from a ground to the TCM case. All seems normal with the jumper connected.
Can I damage the TCM with this external jumper?
I see that the TCM grounds are zone 4, right rear engine block, in the GM Upfitter Manual.
Are there other grounds I should check?
