Loss of Ignition 1 Voltage to the Ignition Coils - keywords 4.8 5.3 6.0 connector crank LR4 LM7 LQ4 LQ9 misfire nostart P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0307 P0308 rough spark stall start
| Subject: | Loss of Ignition 1 Voltage To the Ignition Coils |
| Models: | 2005-2006 Chevrolet Express, Silverado, Suburban, Tahoe |
| 2005-2006 GMC Savana, Sierra, Yukon |
| Equipped with a 4.8, 5.3 or 6.0 engine |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The customer concern may be a intermittent stall, misfire, or crank no start. There may be no trouble codes set.
Recommendation/Instructions:
Complete the current SI diagnostics for any symptoms or trouble codes found. If diagnostics are inconclusive, and a intermittent stall, misfire, or a crank no start can be duplicated, inspect for a loss of Ignition 1 voltage to the ignition coils. Wiggle test the ignition coil harnesses to see if the concern can be duplicated. Inspect splices S160 and S159 for loose connections. Also inspect connectors C148 and C149 for wires breaking near the connector. The pink ignition 1 power feed wire may break inside the insulation near connector C148/C149.
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.
