Air Injection: Testing and Inspection

Chart C-6a:

Chart C-6b:

Diverter Valve Wiring Diagram:

CIRCUIT DESCRIPTION

An electric air control valve solenoid directs air into the exhaust ports or the atmosphere. During cold starts, above 15~C (59~F), the ECM completes the ground circuit and the EDV (Electronic Divert Valve) solenoid and electric air pump are energized. Air is directed to the exhaust ports when the engine is started. When the fuel system goes to CLOSED LOOP or the electric air pump has been ON for greater than 80 seconds, the ECM opens the ground circuit. When the EDV solenoid and electric air pump are de-energized, air is directed to the atmosphere until the electric air pump stops spinning.


TEST DESCRIPTION

Numbers below refer to circled numbers on the diagnostic chart.

1. This is a system performance test. If both the electric air pump and EDV are functioning properly the amount of fresh air flowing past the oxygen sensor will cause a false lean condition (Low O2 Voltage). When the output test is enabled it will only be ON for 5 seconds.
2. Tests for a grounded electric diverter valve circuit. The EDV solenoid is normally closed and should hold vacuum.
3. Checks for voltage from battery through a fuse to the solenoid.
4. Checks for an open control circuit. Field Service Mode will energize the solenoid if the ECM and circuits are normal. In this step, if the test light is ON, circuits are normal and fault is in the valve.
5. Checks for an open control circuit. Field Service Mode will energize the solenoid if the ECM and circuits are normal. In this step, if the test light is ON, circuits are normal and fault is in the relay.