KNOCK SENSOR
The knock sensor is a piezoelectric device attached to the cylinder block that senses pressure from engine knocking conditions. This vibrational pressure is then converted into a voltage signal which is delivered as output. If engine knock occurs, ignition timing is retarded to suppress it.

Circuit Diagram:

Troubleshooting Procedures:

Troubleshooting Hints
1. The MIL is ON or the DTC is displayed on the HI-SCAN PRO under the following condition:
- When the knock sensor signal is not detected, even though the engine is in an overload condition.
- When the knock sensor signal is abnormally low.

Harness Inspection Procedures:

Sensor Inspection
1. Disconnect the knock sensor connector.
2. Measure the resistance between terminals 1 and 2.

Standard value: about 5 MOhm [at 20 °C (68 °F)]

3. If the resistance is zero, replace the knock sensor.

Knock sensor: 19.6 - 24.5 N.m (200 - 250 kg.cm, 14.5 - 18.1 lb.ft)

4. Measure the capacitance between the terminal 1 and 2.

Standard value: 800 - 1600 pF

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Knock Sensor: Testing and Inspection

Circuit Diagram:

Troubleshooting Procedures:

Harness Inspection Procedures:

Use the Manual With the Right Hardware

When to See a Mechanic