P0540 Volvo Intake Air Heater Feedback Circuit
Possible causes
– Intake air heater relay
Tech description
The most common problem that sets code p0540 is the air intake relay
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0540 Volvo 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.
Volvo Vehicle:Volvo C70,Volvo S40,Volvo XC90,Volvo XC70,Volvo XC60,Volvo V70,Volvo V50,Volvo V40,Volvo S90,Volvo S80,Volvo S60