Knock Sensor, checking

The following procedure is used to diagnose Knock Sensor (KS) 1 G61 / Knock Sensor (KS) 2 G66.

Special tools, testers and auxiliary items required

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) J220 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 (GND) connections between engine/transmission/chassis OK.
Ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to → Preliminary check

Start diagnosis

NOTE:

Before disconnecting the Knock Sensor electrical harness connectors, mark the component location.

Fig 1: Identifying Knock Sensor (KS) Electrical Harness Connector

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Disconnect Knock Sensor (KS) 1 G61 electrical harness connector - 1 - or Knock Sensor (KS) 2 G66 electrical harness connector - 2 -.

Checking internal resistance

Fig 2: Knock Sensor Connector Terminals

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Using a Multimeter, check the Knock Sensor terminals 1 to 2 for an internal short.

Specified value: ∞ (Infinity).

If the specified value was not obtained:

If the specified value was obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 Pin VAG1598/31 (Engine Code ATQ ) Test Box 80 Pin VAG1598/22 (Engine Code AHA). Refer to 24 - MULTIPORT FUEL INJECTION (MFI) .

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) J220. Refer to → Engine Control Module (ECM) J220, replacing .

Fig 3: Identifying 3 Pin Electrical Harness Connector Terminals

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Using a Multimeter, Check the Knock Sensor electrical harness connector to the Engine Control Module (ECM) J220 electrical harness connector for an open circuit.

(Engine Code ATQ)

Knock Sensor (KS) 1 G61 electrical harness connector terminals	Engine Control Module (ECM) J220 electrical harness connector T121 terminals or test box sockets
1	106
2	99
3	108

Knock Sensor (KS) 2 G66 electrical harness connector terminals	Engine Control Module (ECM) J220 electrical harness connector T121 terminals or test box sockets
1	107
2	99
3	108

(Engine Code AHA)

Knock Sensor (KS) 1 G61 electrical harness connector terminals	Engine Control Module (ECM) J220 electrical harness connector T80 terminals or test box sockets
1	68
2	67
3	67

Knock Sensor (KS) 2 G66 electrical harness connector terminals	Engine Control Module (ECM) J220 electrical harness connector T80 terminals or test box sockets
1	60
2	67
3	67

Specified value: 1.5 Ω Max.

If the specified value was not obtained:

Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).
Check the wiring connection for damage, corrosion, lose or broken terminals.
If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and the resistance was not OK:

If no malfunction is found in the wiring and the resistance was OK:

Replace the Engine Control Module (ECM) J220. Refer to → Engine Control Module (ECM) J220, replacing .

Final procedures

After repair work, the following work steps must be performed in the following sequence:

End of diagnosis.