P1C12 – Vacuum Pump Relay Stuck Closed

P1C12 Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P1C12 Possible Causes

Faulty Vacuum Pump Relay,Vacuum Pump Relay harness is open or shorted,Vacuum Pump Relay circuit poor electrical connection

P1C12 Description

The Engine Control Module (ECM) monitors the Vacuum Pump Relay. The ECM sets the OBDII code when the Vacuum Pump Relay is not to factory specifications.