Air Injection Pump: Testing and Inspection
SCAN TOOL TESTINGThe engine should be at normal operating temperature in neutral at idle. Using the Tech 1 scan tool, select "Miscellaneous Test" then "Output Test" Select "AIR System" in "Output Test" directory. Select Heated Oxygen Sensor (HO2S) voltages for both Bank 1 and Bank 2 HO2S.
PROCEDURE
Enable the "Output Test" for the AIR system. The "Output Test" will energize the AIR pump for only 5 seconds. When the "Output Test" is enabled, the HO2S voltages for both sensors should remain under 300 mV because air is being directed to the exhaust ports. If the HO2S voltages remain low during the "Output Test," the AIR pump and integral stop valve are operating satisfactorily.
HO2S VOLTAGE HIGH
If the HO2S voltage does not remain low when the "Output Test" is commanded "ON," preform the following inspections.
INSPECT
1. For a seized AIR pump.
2. Hoses, tubes and all connections for leaks and proper routing.
3. For air flow going to the exhaust ports.
4. AIR pump for proper mounting.