Air Injection: Testing and Inspection

Electric Pulse-Air Shut-Off Valve:

AIR System Electrical Diagram:

When there is sufficient manifold vacuum and the electric PULSAIR shut-off valve is energized (circuit #429 completed to ground through the computer), then air is pumped into the exhaust manifolds through the AIR system. An electric air control valve solenoid directs air into the exhaust ports or to the atmosphere. During cold starts, above 15~C (59~F) the PCM completes the ground circuit, and the EDV solenoid and electric air pump are energized. Air is directed to the exhaust ports whenever the engine is started. When the fuel system goes to "Closed Loop" or the electric pump has been "ON" for more than 80 seconds, the PCM opens the ground circuit. When the EDV solenoid and electric air pump are de-energized, air is directed to the atmosphere until the air pump stops spinning.

AIR System Diagnosis (Chart C-6, Part 1 Of 2):

TEST DESCRIPTION (PART 1 OF 2)
Numbers below refer to circled numbers on diagnostic chart.
1. this is a system performance check. When the system switches to "closed loop" operation, the air pump and PULSAIR shut-off valve are turned "OFF".
2. Tests for a grounded electric divert circuit. Normal system light will be "OFF".
3. Checks for an open control circuit. Grounding the diagnostic terminal will energize the solenoid, if the ECM and circuits are normal. In this step, if the test light is "ON", circuits are normal and the fault is in the valve connections or valve.
4. Checks for an open 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.

AIR System Diagnosis (Chart C-6, Part 2 Of 2):

TEST DESCRIPTION (PART 2 OF 2)
Numbers below refer to circled numbers on diagnostic chart.
1. This checks for an open circuit. "Field Service Mode" will energize the solenoid, if the ECM and the circuits are normal. In this step, if the test light is on, the circuits are normal and fault is in the relay.