GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 Bulletins 🢒 Multiple Electrical Concerns - keywords ABS code DTC electrical light lamp PIINSI U0100 U0101 U0106 U0115 U1800 U2100 U2104 U2105 U2106 U2108 speedometer transmission

Multiple Electrical Concerns - keywords ABS code DTC electrical light lamp PIINSI U0100 U0101 U0106 U0115 U1800 U2100 U2104 U2105 U2106 U2108 speedometer transmission

Subject:Multiple Electrical Concerns

Models:2007 GMC Topkick C6500 - C8500
2007 Chevrolet Kodiak C6500 - C8500
with 7.8 (RPO LG4 OR LF8)


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

You may experience a customer that has one or the following concerns:

  1. SES Lamp
  2. ABS Lamp
  3. Transmission Lamp
  4. Multiple Communication U codes
  5. ECM B Fuse Open
  6. Speedometer and Tachometer bouncing.

The SES, ABS, transmission light may be on with a variety of codes including U0115. Dealer may also find a TRC LED is illuminated on the RDU tool, including trucks that are not equipped with traction control

Recommendation/Instructions:

If you experience one of following concerns above or a powertrain or electrical concern that can not be resolved, inspect for a chaffed wiring harness above the A/C compressor on the compressor lines. See Photo Below


Object Number: 2033338 Size: SH

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.