Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0540 Description

The Engine Control Module (ECM) uses an Intake Air Heater (IAH) to warm the incoming air for proper cylinder combustion. The ECM grounds the control coil of the IAH relay to energize the heater during cold operation.

P0540 Information for specific makes

P0540 CHEVROLET
P0540 DODGE
P0540 GMC