Circuit Description

AIR system is used to accelerate the heating process of the catalytic converters by introducing outside air into the exhaust system. Air pump operates on cold engine starts. When PCM energizes the air pump solenoid, manifold vacuum will pull the combination valve up and allow air from air pump to flow into the exhaust manifold. PCM monitors the air pump solenoid circuit for low and high voltage faults. DTC will set when air pump solenoid is commanded off and feedback voltage at PCM is low. Air pump solenoid resistance is 38-61 ohms.

DTC will set if air pump solenoid voltage is less than 1.25 volts when air pump solenoid is commanded off. Diagnostic runs continuously with engine running and air pump solenoid commanded off.