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SES Light On And DTC P0540 - keywords 6.6L air connector connection control ECM fuse glow GPCM heat heater intake MIL module plug SES start UBEC

Subject:SES Light On And DTC P0540

Models:2006-2007 Chevrolet Silverado
2006-2007 GMC Sierra
Classic Body Style Vehicles Equipped with the 6.6 LLY or LBZ Diesel Engine.



This PI was updated to include the 2007 model year. Please discard PIP3958.


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

Condition/Concern:

A SES light on with trouble code P0540 found. A loose connection at the Intake Air Heater (IAH) Fuse may induce a P0540.

Recommendation/Instructions:

Complete the current SI diagnostic for any trouble code or symptom found.

During diagnosis for the P0540, inspect for a loose connection at the IAH 175 amp Mega-fuse. The 175 amp fuse is located in the Under hood Bused Electrical Center. The left fender upper brace and the secondary UBEC cover need to be removed to inspect the IAH fuse.

Clean and tighten the connection at the 175 amp fuse and evaluate repairs.

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.