Knock Sensors, Checking
Special tools and workshop equipment required
- Multimeter.
- Wiring diagram.
Test requirements
- The mounting bolt of Knock Sensor (KS) 1 -G61- /Knock Sensor (KS) 2 -G66- tightened to 20 Nm.
- The Engine Control Module (ECM) - J623- fuses OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground connections between engine/transmission/chassis OK.
- Ignition switched OFF.
Test procedure
-- Observe safety precautions. Refer to SAFETY PRECAUTIONS
-- Observe Clean Working Conditions. Refer to CLEAN WORKING CONDITIONS
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .
Procedure
Before disconnecting the Knock Sensor -- electrical harness connectors, mark the component location.
-- Disconnect Knock Sensor (KS) 1 -G61- electrical harness connector -1- or Knock Sensor (KS) 2 -G66- electrical harness connector -2-.
Checking internal resistance
-- Using a multimeter, check the resistance of terminals 1 to 2 of both knock sensors for an internal short.
Specified value: ∞ (Infinity).
If the specified value was Not obtained:
-- Replace the faulty Knock Sensor (KS) 1 -G61- or Knock Sensor (KS) 2 -G66-.
If the specified value was obtained:
Checking wiring
If the manufacturers test box is being used. Perform the following step.
-- Install the test box.
If the manufacturers test box is not being used. Perform the following step.
-- Remove the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
-- Using a multimeter, Check the knock sensor electrical harness connectors to the Engine Control Module (ECM)J623 electrical harness connector T60 for an open circuit.
| Knock Sensor (KS) 1 -G61- electrical harness connector terminals | Engine Control Module (ECM) electrical harness connector T60 terminals or test box sockets |
|---|---|
| 1 | 39 |
| 2 | 54 |
| 3 | 52 |
| Knock Sensor (KS) 2 -G66- electrical harness connector terminals | Engine Control Module (ECM) electrical harness connector T60 terminals or test box sockets |
|---|---|
| 1 | 9 |
| 2 | 24 |
| 3 | 52 |
Specified value: 1.5 Ω Max.
If the specified value was Not obtained:
-- Check the wiring connection for an open circuit, high resistance or short circuit to voltage or ground.
-- Check the wiring connection for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
If no malfunction is found in the wiring and the sensor resistance is OK:
-- Replace the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .