P1503 Buick Theft Deterrent Fuel Enable Signal Not Correct

P1504 Buick Intake Air Control Circuit Malfunction

Possible causes
– Idle Air Control Valve harness is open or shorted
– Idle Air Control Valve circuit poor electrical connection
– Faulty Idle Air Control Valve
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1504 Buick Description

The Idle Air Control Valve (IACV) is used to control engine idle speed and allows air to bypass the throttle plate. The amount of air allowed to bypass is determined by the Powertrain Control Module (PCM) and controlled by a duty-cycle signal.

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