Faulty Signal. Intermittent Fault

Checking Signal Cable
To access knock sensor (KS) connectors, remove the following:

- Air cleaner (ACL) cover with mass air flow (MAF) sensor.
- Reinstall after fault-tracing.
- Ignition OFF.
- Wait for approx. 150 seconds (cars with immobilizer 245 seconds).
- Disconnect knock sensor.
- Connect an ohmmeter between knock sensor connector terminal 1 and ground.
- The ohmmeter should read approx. 1 M ohms.

If reading is OK:
^ Proceed to: Checking Cables and Terminals section below.

If reading is incorrect:
^ Check cable between knock sensor terminal 1 and engine control module (ECM) # A2 (EFI-143) or # A30 (EFI- 433) for an intermittent short-circuit to ground.

Checking Cables and Terminals
- Check knock sensor and engine control module connectors for loose connections according to HHHB5 and contact resistance and oxidation.
- Check cable between knock sensor terminal 1 and engine control module # A2 (EFI-143) or # A30 (EFI-433) for an intermittent open-circuit and an intermittent short-circuit to ground.
- Check cable between knock sensor connector terminal 2 and engine control module # A17 for an intermittent open-circuit and an intermittent short-circuit to ground.
- Proceed to: Fault-tracing Information section below.

Fault-tracing Information
For intermittent faults fault-tracing is not followed by a verification because the fault is not present at this moment.

- Do you want to repeat fault-tracing?

Yes:
^ Proceed to: Checking Signal Cable section above.

No:
^ Operation done.