Intake Air Heater ‘A’ Circuit High
Table of contents
P0542 JEEP 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
How do I fix code P0542 JEEP?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the P0542 JEEP code
The cost of diagnosing the P0542 JEEP code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
The Engine Control Module (ECM) sends a bias voltage on diagnostic circuits one and two. If this voltage is high with the relay ON, DTC P0542 will set. The ECM will only store info on first failure, It triggers the SES light on the second failure.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0542 JEEP 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.