Air Injection: Testing and Inspection

Chart C-6 A.I.R. Managment Check (PEDES):

Wiring Diagram for Chart C-6 A.I.R. Managment Check (PEDES):

Circuit Description:
Air management is controlled by a pressure operated port valve and a converter valve, each with an ECM controlled solenoid. When the solenoid is grounded by the ECM, AIR pressure will activate the valve and allow pump air to be directed as follows:
Neither solenoid grounded by the ECM - Air pump air to atmosphere.
Converter solenoid grounded by the ECM - Air pump air to converter.
Port solenoid grounded by the ECM - Air pump air to exhaust ports.

Test Description: Numbers below refer to circled numbers on the diagnostic chart.
1. This is a system functional check. Air is directed to ports during open loop and all engines start in "Open Loop" even on a warm engine. Since the air to the ports may be very short, prepare to observe port air prior to engine start up. This can be done by squeezing a hose.

2. This should normally set a Code 22. When any code is set, the ECM opens the ground to the converter solenoid and allows air to divert. This checks for ECM response to a fault. A ground in the control 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 solenoid circuit. Test light "OFF" would indicate the circuit is normal and fault is in the valve.