DTC P0401 Setting Only When PTO Idle Up Feature Is Engaged - keywords 6.6 6.6L control diesel EGR ECM engine exhaust gas LMM MIL recirculation SES set speed switch
| Subject: | DTC P0401 Setting Only When PTO Idle Up Feature Is Engaged |
| Models: | 2007-2008 Chevrolet Kodiak |
| 2007-2008 GMC Topkick |
| Equipped with the 6.6 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:
A dealer may encounter a vehicle setting only DTC P0401. The information in this PI only pertains to vehicles that set P0401 when the PTO/idle up feature is turned on.
Recommendation/Instructions:
If DTC P0401 only sets when the PTO or idle up feature is turned on, check the actual engine RPM when the PTO/idle up is engaged. If the RPM is set near or at 1000 rpm, P0401 may be induced during PTO/idle up use.
Engineering is investigating DTC P0401 when it sets when the PTO is engaged.
At this time there is a work around to repair the vehicle. If the idle speed is set at or above 1200 RPM, DTC P0401 should no longer set. Evaluate the concern after PTO set speed is changed.
This PI will be updated when new information is received.
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.
