P0540 Audi 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 Audi 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.
Audi Vehicle:Audi A1,Audi A3,Audi A1,Audi A3,Audi A1,Audi A3,Audi A4,Audi A5,Audi Q3,Audi A5,Audi Q5,Audi A3,Audi A4,Audi A5,Audi TT,Audi Q3,Audi Q5,Audi S3,Audi TTS,Audi RS 3,Audi TT RS,Audi A7,Audi Q7,Audi A8,Audi A6,Audi S4,Audi S5,Audi Q5,Audi S6,Audi S8,Audi S5,Audi A8,Audi R8 V8,Audi RS 5,Audi S6,Audi R8 V10,Audi R8 GT,Audi A8L