No Crank / No Start At Times - keywords code communication DTC high lan speed U2100
| Subject: | No Crank/No Start At Times |
| Models: | 2007 Cadillac Escalade, Escalade ESV, Escalade EXT |
| 2007 Chevrolet Avalanche, Suburban, Tahoe |
| 2007 GMC Yukon, Yukon XL, Yukon Denali |
This PI was superseded to update Recommendation/Instructions. Please discard PIT3993A.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may experience a "No Crank" condition at times. During diagnosis, there may be no communication with any module on the GM High Speed Lan or multiple GM High Speed Lan "loss of communication" codes.
Recommendation/Instructions:
Some reports from the field have found the GM High Speed Lan terminating resistor shorting out and pulling down the GM High Speed Lan data line. If you experience this concern, remove the terminating resistor and swap it with a known good vehicle and re-test the vehicle, If the concern goes away, replace the terminating resistor.
When replacing the terminating resistor, please use GM part number: 88988999
Note: The resistance of the terminating resistor should be approximately 121 ohms.
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.
