Mazda 6 Service Manual: Idle air control (iac) valve inspection

Note

• Perform the following inspection only when directed.

Operation Test

Carry out the Idle Air Control Inspection. (See Idle Air Control System Inspection.)

• If not as specified, perform the further inspection for the IAC valve.

Resistance Inspection

1. Disconnect the negative battery cable.

2. Disconnect the IAC valve connector.

3. Measure the resistance between the IAC valve terminals using an ohmmeter.

• If not as specified, replace the IAC valve. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
• If as specified but the Operation Test is failed, carry out the Circuit Open/Short Inspection.

Specification

Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION.)

2. Inspect the following wiring harnesses for open or short (continuity check).

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the harness.

- IAC valve terminal A (harness-side) and PCM terminal 4G

- IAC valve terminal B (harness-side) and PCM terminal 4J

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the harness.

- IAC valve terminal A (harness-side) and power supply

- IAC valve terminal A (harness-side) and GND

- IAC valve terminal B (harness-side) and power supply

- IAC valve terminal B (harness-side) and GND