Duramax Diesels With SES Light And DTC P0402 - keywords 6.6 air diesel DTC EGR engine excessive exhaust flow gas gasket intake leak LMM low MAF noise power recirculation rough valve
| Subject: | Duramax Diesels with SES Light and DTC P0402 |
| Models: | 2007-2008 Chevrolet Express |
| 2007-2008 GMC Savana |
| Equipped with the 6.6L Duramax Diesel engine RPO code LMM |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The customer concern may be SES light on, a loss of power, and DTC P0402.
Recommendation/Instructions:
Complete the current SI diagnostics for any trouble code or symptom found. If the diagnostic is inconclusive, and the P0402 diagnostic has not led to a repair, please do not replace any EGR components.
SI diagnostics should still be completed for P0402 because it's still possible to have a air intake duct leak, air filter modification, or a Charge Air Cooler leak inducing the trouble code.
If diagnostics are inconclusive, engineering is investigating the P0402.
This PI will be updated when more information becomes available.
If P0402 diagnostics are inconclusive please complete a Field Product Report following bulletin number 02-00-89-002F.
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.
