Duramax Diesels With SES Light And DTC P0402 - keywords 6.6 air cal calibration 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 |
This PI was superseded to update Recommendation/Instructions. Please discard PIP4296A.
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. SI diagnostics should be completed for P0402 because it's still possible to have an air intake duct leak, air filter modification, or a Charge Air Cooler leak inducing DTC P0402. 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.
Engineering has released a new calibration to address DTC P0402. If the current SI diagnostics for P0402 were inconclusive install the new calibration and evaluate the concern.
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.
