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Makes 🢒 GMC_Truck 🢒 2007 🢒 Sierra Denali 🢒 Bulletins 🢒 SES MIL DTC P154B And/Or P064C - keywords air check engine hard heater intake IPC lamp light start

SES MIL DTC P154B And/Or P064C - keywords air check engine hard heater intake IPC lamp light start

Subject:SES MIL DTC P154B and/or P064C

Models:2007-2008 Chevrolet Silverado
2007-2008 GMC Sierra
With 6.6L RPO LMM Engine


This PI was superseded to update Title and Recommendation/Instructions. Please discard PIT4581.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Some owners may comment of the Check Engine Light displayed on the IPC. When checking for DTCs the ECM will have set a P154B, P064C, and/or a hard start concern in very cold ambient temperatures. This concern could be caused by a loose connection at the 125 or 175 Amp Mega Fuse located on the right side of the cowl as shown below.


Object Number: 2074826 Size: SH

Recommendation/Instructions:

If there are any signs of damage, replace and tighten the Mega Fuse to the proper specifications listed in SI.

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.