P0542 Buick Intake Air Heater Relay 1 High

P0543 Buick Intake Air Heater Incorrect Voltage

Possible causes
– Faulty Intake Air Heater relay
– Faulty Intake Air Heater
– Intake Air Heater harness is open or shorted
– Intake Air Heater circuit poor electrical connection
What about the obd code?
The Engine Control Module (ECM) sends a bias voltage on diagnostic circuits one and two. If this voltage is not pulled low when the relay is OFF, or is high with the relay ON, DTC P0543 Buick will set. The ECM will only store info on first failure, It triggers the SES light on the second failure.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0543 Buick 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.

Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera