Possible Causes
Faulty Intake Air Heater (IAH) Relay
Faulty Intake Air Heater
Intake Air Heater Relay harness is open or shorted
Intake Air Heater Relay circuit poor electrical connection
Intake Air Heater harness is open or shorted
Intake Air Heater circuit poor electrical connection
الأسباب المحتملة
Possible Symptoms
Engine Light ON (or Service Engine Soon Warning Light)
الأعراض المحتملة
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. The control module will command the IAH ON when the engine coolant temperature is below 40 C (104 F). The power to the IAH heater is supplied by the battery positive voltage circuit through the IAH relay.