Signal Missing. Permanent Fault

Checking Signal Cable Resistance To Ground
- Ignition off.
- Wait for approx. 150 seconds (cars with immobilizer 245 seconds).
- Disconnect idle air control (IAC) valve.
- Connect an ohmmeter between ground and idle air control valve connector terminal 1.
- The ohmmeter should read 10 - 20 k ohms.

If reading is OK:
^ Proceed to Checking Idle Air Control Valve section below.

If reading is incorrect:
^ Proceed to test step below.





Checking the engine control module connector
- Ignition off.
- Idle air control valve disconnected.
- Check engine control module (ECM) connector for contact resistance and oxidation and remedy.
- Engine control module connected.
- Connect an ohmmeter between ground and idle air control valve connector terminal 1.
- The ohmmeter should read 10 - 20 k ohms.

If reading is OK:
^ The diagnostic trouble code was caused by poor contact in the engine control module connector.
^ Then proceed to Verification section below.

If reading is incorrect:
^ Check cable between idle air control valve terminal 1 and engine control module # A25 for an open-circuit.
^ Then proceed to Verification section below.





Checking Idle Air Control Valve
- Ignition off.
- Idle air control valve disconnected.
- Connect an ohmmeter between idle air control valve connector terminals 1 and 2.
- Read off value.
- Then connect an ohmmeter between idle air control valve connector terminals 2 and 3.
- Read off value.
- The ohmmeter should read 9 - 14 ohms at +20°C in both cases.

If reading is OK:
^ The diagnostic trouble code (DTC) has been caused by poor contact in the idle air control valve connector. Check connector for contact resistance, oxidation and remedy.
^ Then proceed to Verification section below.

If reading is incorrect:
^ Try a new idle air control valve.
^ Then proceed to Verification section below.





Verification
- After carrying out the repair, check that the fault has been remedied as follows.
- Ignition on.
- Activate idle air control valve.
- A "clicking sound" is heard from the idle air control valve when it is activated.
- Is the idle air control valve working?

If reading is OK:
^ Fault corrected

If reading is incorrect:
^ Proceed to test step below.

Fault-tracing Information
The verification result shows that the fault persists.

- Do you want to exit fault-tracing?

Yes:
^ Fault not corrected

No:
^ Return to Checking Signal Cable Resistance To Ground section above.