K 1500 Truck 4WD V8-5.3L VIN T (1999)
Air Injection Pump: Description and Operation
The AIR pump is an electric type pump which requires no periodic maintenance.
The engine should be at normal operating temperature in neutral at idle. Using the scan tool enable the AIR pump system. Select HO2S voltages for both
Bank 1 and Bank 2 HO2S. The HO2S voltages for both sensors should remain under 350 mV because air is being directed to the exhaust ports. If the
HO2S voltages remain low during the Output Test, the AIR pump, solenoid and shut off valve are operating satisfactorily. If the HO2S voltage does not
remain low when the AIR pump is enabled, inspect for the following:
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For voltage at the Air Pump when it is energized.
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A seized AIR pump.
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The hoses, vacuum lines, pipes and all connections for leaks and proper routing.
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Air flow going to the exhaust ports.
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AIR pump for proper mounting.
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Hoses and pipes for deterioration or holes.
