Fast Idle Control Test

Fast Idle Control Test





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





3. Disconnect the # 23 vacuum hose from the intake manifold and check the vacuum.
- If there is no vacuum, check the vacuum port.
4. Turn the ignition switch OFF.





5. Connect the PGM-FI test harness "B" connector to the main wire harness only, not the ECU.





6. Disconnect the # 23 vacuum hose from the vacuum hose manifold and connect a vacuum pump to the hose.
7. Apply vacuum to the hose.

It should hold vacuum.

- If it does not hold vacuum, replace the solenoid valve and re-test.
8. Turn the ignition switch ON.
9. Apply vacuum to the hose.

It should hold vacuum.

- If it does not hold vacuum, repair short in Red/Green wire between the solenoid valve and ECU.

NOTE: On cars with automatic transmission, also inspect short in Green wire between the A/T idle control solenoid valve and ECU.





10. Connect B4 terminal to A18 terminal.
11. Apply vacuum to the hose.

It should not hold vacuum.





- If it holds vacuum, turn the ignition switch OFF. Disconnect the 6P connector, then attach the positive probe of the voltmeter to the Black/Yellow terminal, and the negative probe to the Red/Green terminal. Turn the ignition switch ON.
- 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.
- If there is no voltage, repair the open in the Black/Yellow wire between the solenoid valve and the No.1 fuse.
- If there is voltage, repair the open in the Red/Green wire between the solenoid valve and the ECU.