Air Injection: Testing and Inspection

Chart C-6A:

Chart C-6A Wiring Diagram:

The air management system is controlled by a pressure operated port and an air switching valve (converter valve). Both valves are controlled by the ECM. When the solenoid is grounded by the ECM, the A.I.R. pump pressure will activate the valve and pump air will be directed as follows:

^ Cold Mode Operation: The port (switch) solenoid is energized which in turn opens the port valve, and allows air to flow into the exhaust ports.

^ Warm Mode Operation: The port (switch) solenoid is de-energized and the converter (divert) solenoid is energized. This closes the port valve and keeps the converter valve seated, and forces air to flow past the converter valve to the catalytic converter.

^ Divert Mode Operation: Both solenoids are de-energized, which opens the converter valve, allowing air to take the path of least resistance. The flow is through the divert/relief tube to atmosphere.


TEST DESCRIPTION: The numbers below refer to circled numbers on the diagnostic chart.

1. This is a system functional check. Since all engines start in open loop, air is directed into the ports. Squeeze the air hose prior to starting the engine to check port air operation.

NOTE: Some engines will divert air to the exhaust ports for a very short period, and may need to have the steel air tubes disconnected to check air flow.

2. This should set a code 22. When any code is set, the ECM opens the ground to the A.I.R. control valve and allows air to divert. This checks for ECM response to a fault. A ground in the A.I.R. control valve circuit to the ECM would prevent diversion action.

3. This checks for a grounded circuit to the ECM. Test light "OFF" is normal and indicates the circuit is not grounded.

4. This checks for an open in the solenoid control circuits. Grounding the test terminal, should ground both solenoid circuits. Normally, the test light should be ON. This indicates that the problem is not in the ECM or wiring, but at the solenoid connections or control valve itself.

5. This checks for a grounded port solenoid circuit. Test light "OFF" indicates that the circuit is normal, and the fault is in the valve.

NOTE: Once the test sequence is completed, clear codes and verify NO "SERVICE ENGINE SOON" light exists.