Chart C6B - Air Management Check (PEDES Valve)
Air management is controlled by a port valve and a converter valve, each with an ECM controlled vacuum solenoid. When solenoid is grounded by ECM, air pressure will activate valve and allow pump air to be directed either to the solenoid that is grounded or port solenoid that may be also grounded.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- This is a system functional check. Air is directed to ports during "open loop" and all engine starts are in open loop (even on a warm engine). Since the air to the ports time is very short on some engines, prepare to observe port air prior to engine start up. On some engines, this can be done by squeezing a hose. On others, steel pipes have to be disconnected.
- This should normally set a Code 22. When any code is set, the ECM opens the ground to the air control valve and allows air to divert. This checks for ECM response to a fault that may exist. A ground in the control valve circuit to the ECM would prevent diverter action.
- This checks for a ground circuit to the ECM. If test light is off, this is normal and would indicate the circuits are not grounded.
- 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 the switching valve itself.
- Checks for a grounded switching valve circuit. If test light is off, this would indicate the circuit is normal and fault is in the switching valve.