Air Injection: Testing and Inspection

Chart C-6 1 Of 2:

Control Valve Wiring Diagram:

CIRCUIT DESCRIPTION:

This system uses a single bed converter and air management is controlled by an air control valve.
When grounded by the ECM, the solenoid allows the valve to direct air to the exhaust ports. When de-energized, air diverts to the atmosphere. Air will go to the ports provided the valve has a ground to the ECM and good manifold vacuum.

TEST DESCRIPTION:

The numbers below refer to the circled numbers on the diagnostic chart.

1. This is a system performance test. When the vehicle goes into "Closed Loop", air will switch from the ports and divert.
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.

CAUTION: Not all "SCAN" testers are compatible with every system. A "SCAN" tool that produces faulty readings should NOT be used, and the problem should be reported to the tool manufacturer. Use of a faulty "SCAN" tool can result in improper diagnosis and unnecessary component replacement. Follow the proper instructions, located in the owners manual, for the specific "SCAN" tool being used.

Chart C-6 2 Of 2:

Control Valve Wiring Diagram:

CIRCUIT DESCRIPTION:

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 ECM 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 ECM 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.

TEST DESCRIPTION:

The numbers below refer to the circled numbers on the 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.

CAUTION: Not all "SCAN" testers are compatible with every system. A "SCAN" tool that produces faulty readings should NOT be used, and the problem should be reported to the tool manufacturer. Use of a faulty "SCAN" tool can result in improper diagnosis and unnecessary component replacement. Follow the proper instructions, located in the owners manual, for the specific "SCAN" tool being used.