Subject: | Intermittent No Crank And/Or Discharged Battery |
Models: | 2007-2008 Cadillac Escalade Models |
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
2007-2008 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Some owners may comment of an intermittent no crank and/or dead battery. This concern could be caused by a loose connection at the 175 Amp Mega Fuse located on the passenger side of the cowl, as shown below. GM Engineering has found that over time the mega fuse to cable nuts may relax causing a poor connection. A poor connection at this fuse can either cause the battery not to charge while the vehicle is running and/or no power to the UBEC or Starter when trying to crank the vehicle. In either case, the end result may be a no crank concern.
Remove the Mega Fuse nuts and inspect the fuse, cables, nuts and holder for corrosion, arcing, or signs of overheating. Replace any damaged components and torque the mega fuse nuts to the updated specifications listed in SI.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.