Subject: | Battery Draw, ISLPS Fuse Blown, Courtesy or Sunshade Lamps Inop |
Models: | 2007-2008 Cadillac Escalade, EXT, ESV |
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
2007-2008 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL |
This PI was superseded to update model years. Please discard PIT4050B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Some customers may comment the courtesy/reading or sunshade lamps are inoperative and the ISLPS/IS Lamps fuse is blown. The ISLPS fuse is a power feed to the BCM and it uses the power from this fuse to feed some of its outputs. One of the outputs is the inadvertent power supply to the courtesy/reading/sunshade lamps on circuit 6815 orange. If this circuit (6815) shorts to ground the ISLPS/Is Lamps fuse may blow.
To correct this concern, repair the short and reroute harness so it does not reoccur. In some cases, if circuit 6815 is chaffing/intermittently/or partially shorted to ground it may not blow the ISLPS/IS Lamps fuse but intermittently wake up the BCM and cause a battery draw.
Reports of this circuit chaffing or shorting to ground at the overhead DVD screen or at the sunshades have been received.
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.