System Diagnosis - Vin F (Port Fuel Injection)

Chart C-6:

Air Management Check Wiring Diagram:

AIR MANAGEMENT CHECK (PEDES VALVE)

CIRCUIT DESCRIPTION:

The air management system is controlled by a pressure operated port and an air switching valve (converter valve). Both valves are controled by the ECM. Pump air will be directed as follows:
During cold start, the port solenoid is energized, which opens the port valve, and air is directed into the exhaust ports. As coolant temperature increases, or system goes into "Closed Loop", the port solenoid is de-energized, and the converter solenoid is powered, which allows the converter valve to be seated, and air is forced to the catalytic converter. If both solenoids are powered off, the air will be diverted to the atmosphere.




TEST DESCRIPTION: The numbers below refer to circled numbers on the diagnostic chart.

1. This is a system functional check. Since all engines start in open loop, air is directed into the ports. Squeeze the air hose prior to starting the engine to check port air operation.
2. This should 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 the divert action.
3. This checks for a grounded circuit to the ECM. Test light off is normal and indicates circuit is not grounded.
4. This 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. this indicates that the problem is not in the ECM or wiring, but at the solenoid connections or valve itself.
5. This checks for a grounded solenoid circuit. Test light off indicates that the circuit is normal, and the fault is in the valve.

NOTE: Once the test sequence is completed, clear codes and verify NO "Service Engine Soon" light exists.


AIR PUMP

TEST DESCRIPTION:

1. Remove the hose from A.I.R. Injection Manifold Check Valve prior to starting the engine. Start engine and accelerate to approximatley 1500 rpm and observe air flow from hose. If air flow increases as the engine rpm increases, the air pump is OK. If not proceed as follows:
2. Check to make sure air pump is not seized.
3. Check for proper drive belt tension.
4. Check the air pump for a leaking pressure relief valve. Air leakage may be heard from this valve with engine running.
5. Check hoses, tubes, and connections for proper routing and no leakage.
6. Check air injection pump for proper mounting.


CHECK VALVE

TEST DESCRIPTION:

Whenever a hose is removed from a check valve, the check valve should be inspected. Replace check valve if the hose shows signs of exhaust gas contamination. Little or no air should be felt coming from check valve with engine running at idle. Air should flow freely through the valve towards the engine cylinder head (one direction only).