Diagnostic Aids

Inspect for any of the following conditions:

• The resistance of the AIR pump relay coil (across terminal 85 and terminal 86) is 50-70 ohms at 20°C (68°F). In the normal unenergized state, the resistance of the open relay contacts (across terminal 30 and terminal 87) is infinite.
• The AIR pump relays electrical contacts may be pitted and sticking. Replace the relay if tapping gently on the relay or wiggling the relay causes a change in the relays operation.
• The performance of the AIR pump relay may be affected by temperature. Check the relay after sitting outside overnight and after running the engine 30 minutes.
• An intermittent malfunction may be caused by a fault in an AIR system electrical circuit. Inspect the wiring harness and components for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections .