Loss of Power, Hard Start, or Stabilitrak Light On - keywords 08 5.3 C0240 chafe chafing conduit DIC DTC harness LH8 MIL no P0335 P03366 P0651 retainer SES stability start SYS wire wiring

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

A dealer may encounter a 2008 H-3 Hummer with a C0240, P0651, loss of power, hard start, or the stabilitrak light illuminated.

This condition may occur more often when the vehicle is turned to the left.

Complete the current SI diagnostic for any trouble code or symptom found.

If diagnostics are inconclusive inspect for a wire chafe at the lower front of engine wiring harness retainer.

There is a plastic wire retainer located at the front of the engine, just forward of the oil pan. The retainer supports a wiring harness that crosses from the left to right side of the engine. The crank sensor and starter circuits are located in this harness.

The vehicle skid plates need to be removed to access the wiring harness retainer. On the right side (passenger side) of the engine the plastic retainer has a molded bend or curve. Inspect the harness and be sure the harness is located in the retainer correctly. If the harness has begun to ride on top of the molded bend, it is possible for the edge of the retainer to push on the wires and induce chafes.

Inspect the harness for proper positioning and reposition if needed. If the wires are found to be chafed make repairs using the current SI procedure for wiring repairs. Tape the harness conduit closed, and install harness in its correct position.

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.