SES MIL DTC U0100 U0101 U0105 and/or U0106 - keywords communication erratic low power shift
| Subject: | SES MIL DTC U0100 U0101 U0105 and/or U0106 |
| Models: | 2004-2005 Chevrolet Silverado |
| 2004-2005 GMC Sierra |
| with 6.6L RPO LLY engine |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some owners may comment of a SES MIL on and if DTCs are checked with the Tech 2 a U0100, U0101, U0105, and/or U0106 will be set. The ECM, TCM, FICM, and Glow Plug Controller communicate between each other on circuits 2361 and 2362 (CAN Buss), the Tech 2 does not communicate on these circuits.
Recommendation/Instructions:
In most cases, if all the DTCs set it could be caused by the Can Buss circuits shorted to ground. Cases for either of these circuits shorting to ground at the FICM/Alternator bracket have been reported. Before replacing any parts perform a thorough visual inspection of this wiring harness near the FICM/Alternator bracket and repair as necessary if shorted.
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.
