Duramax Diesels With SES Light And DTC P0402 - keywords 6.6 air 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 |
This PI was superseded to update Rcommendation/Instructions. Please discard PIP4296.
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. Inspect all Charge Air Cooler hoses and verify they are completely seated and clamped correctly. A loose snap ring connection at the Intake Air Valve may also induce P0402.
ngineering has investigated the P0402 concerns and is in process of updating the EGR calibrations. Calibrations are due to be released on or by the first TIS2000 update in February.
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.
