ATSG CONFIRMED FIX - OCTOBER 2022
2009 GMC K2500 6.0L 6L90
Complaint: Vehicle was having wrong gear starts and they were being commanded
Cause: Wires in the harness were rubbed bare at the alternator housing
Correction: Repair the wires that were bare and insulated the harness from further damage
Part numbers related to the repair: NA
Year Make and Model of the Vehicle: 2009 GMC K2500 6.0L
Mileage: NA
Shop Name: Mr. Transmission
Transmission: 6L90E
Additional Notes: with scanner technician noticed that the higher gear starts were being commanded with no trouble codes stored, had shop look at data and really did not see anything that was looking to be wrong, had them check the alternator for any possible ac voltage coming out of it possibly causing EMI to get into the system, that is when he went to the alternator and found the damage to the harness, after repairing the harness and insulating it from any further damage, road tested vehicle and the problem was corrected.
Pictures/Diagram: Included below.
Find thousands of Confirmed Fixes, Quick Reference Guides, Bulletins & Video Tutorials in the ATSG Member exclusive Tech Library along with unlimited calls into the tech hotline by joining ATSG today: https://bit.ly/ATSGmembership
