A/C Idle Control Test

A/C Idle Boost Test





1. Check the vacuum line for improper connection, cracks, blockage or disconnected hoses.
2. Start the engine and allow to idle.





3. Disconnect the vacuum hose between the A/C idle boost valve and the air chamber from the A/C idle boost valve and connect a vacuum gauge to the valve.

There should be no vacuum.





- If there is vacuum, disconnect the # 19 vacuum hose from the A/C idle boost valve and connect the vacuum gauge to the hose.
- If there is no vacuum, replace the A/C idle boost valve and re-test.
- If there is vacuum, go to solenoid valve test II.
4. Turn the A/C switch and blower switch ON, then check that the compressor and the condenser cooling fan work.
There should be vacuum.
- If there is no vacuum, disconnect the # 19 vacuum hose from the A/C idle boost valve and connect the vacuum gauge to the hose.
- If there is vacuum, replace the A/C idle boost valve and re-test.
- If there is no vacuum, go to solenoid valve test I.


Solenoid Valve Test I:

1. Start the engine and allow to idle.





2. Disconnect the # 12 vacuum hose from the intake manifold and check the vacuum.
- If there is no vacuum, check the vacuum port.
3. Disconnect the 6P connector.





4. Attach the positive probe of the voltmeter to the Black/Yellow terminal, and the negative probe to the Red terminal.
5. Turn the A/C switch and blower switch ON, then check that the compressor and the condenser cooling fan work.
- If there is voltage, replace the solenoid valve and re-test.
- If there is no voltage, attach the positive probe of the voltmeter to the Black/Yellow terminal, and the negative probe to body ground. Check for voltage.
- If there is no voltage, repair the open in the Black/Yellow wire between the solenoid valve and No. 1 fuse.
- If there is voltage, inspect for an open in the Red wire between the solenoid valve and the ECU. If the wire is OK, see ECU troubleshooting.

Solenoid Valve Test II
1. Start the engine.
2. Disconnect the 6P connector.





3. Attach the positive probe of the voltmeter to the Black/Yellow terminal, and the negative probe to the Red terminal.
- If there is voltage, inspect for a short in the Red wire between the solenoid valve and the ECU. If the wire is OK, see ECU troubleshooting.
- If there is no voltage, replace the solenoid valve and re-test.