Air Injection: Testing and Inspection

Fig. 002 - Wiring Diagram for Chart C-6A Air Management Check. VIN C:

CHART C-6A, AIR MANAGEMENT CHECK

Air Management is controlled by Air Divert and Air Switching Valves, each with an ECM controlled vacuum solenoid. When the solenoid is grounded by the ECM, manifold vacuum will activate the valve and allow pump air to be directed as follows:
a. Air divert solenoid not grounded by ECM - Air pump air diverted.
b. Air divert solenoid grounded by ECM - Air pump air to Air Switching Valve.
c. Air switching solenoid not grounded by ECM - Air pump air to converter.
d. Air switching solenoid grounded by ECM - Air pump air to exhaust ports.
Loss of vacuum would cause air to be diverted to air cleaner.

Fig. 001 - Chart C-6A Air Management Check.:

1. This is a system functional check. Air is directed to ports during open loop and all engine starts in open loop, even on a warm engine. Since the air to the ports time is sometimes very short, prepare to observe port air prior to engine start-up. This can be done by squeezing the hose.
2. This should normally set a Code 23. When any code is set, the ECM opens the ground to the Air Divert Valve and allows air to divert. This checks for ECM response to a fault. A ground in the divert valve circuit to the ECM would prevent divert action.
3. This checks for a grounded circuit to the ECM. Test light "OFF" is normal and would indicate the circuit is not grounded.
4. 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" which indicates the problem is not in the ECM or wiring, but at the solenoid connections or valve itself.
5. Checks for a grounded switching valve circuit. Test light "OFF" would indicate the circuit is normal and fault is in the valve.