Knock Sensor (KS) 1 G61/Knock Sensor (KS) 2 G66 , checking

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

The following procedure is used to diagnose all Knock Sensors.

Special tools, testers and auxiliary items required

Multimeter.
Wiring diagram.

Test requirements

The mounting bolt of Knock Sensor (KS) 1 G61/Knock Sensor (KS) 2 G66 tightened to 20 Nm.

Fig 1: Identifying Main Fuse Panel

Courtesy of VOLKSWAGEN UNITED STATES, INC.

The Motronic 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.

Procedure

Fig 2: Removing Engine Cover

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Remove the engine cover with air filter → 24 MULTIPORT FUEL INJECTION (MFI) .

NOTE:

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

Fig 3: Identifying Green Knock Sensor (KS) 1 G61 Electrical Harness Connector & Gray Knock Sensor (KS) 2 G66 Electrical Harness Connector

Courtesy of VOLKSWAGEN UNITED STATES, INC.

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

Checking internal resistance

Fig 4: Identifying Engine Speed (RPM) Sensor G28 Terminals

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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:

Replace the faulty Knock Sensor (KS) 1 G61/Knock Sensor (KS) 2 G66 → 15 - ENGINE - CYLINDER HEAD, VALVETRAIN .

If the specified value was obtained:

Checking wiring

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

Install the test box. Refer to → 24 MULTIPORT FUEL INJECTION (MFI) .

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

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

Fig 5: Identifying 3-Pin Connector Terminals 1 & 3

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

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

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

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:

Replace the faulty Knock Sensor (KS) 1 G61/Knock Sensor (KS) 2 G66 → 15 - ENGINE - CYLINDER HEAD, VALVETRAIN .

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

Replace the Motronic Engine Control Module (ECM) J220. Refer to → Motronic Engine Control Module (ECM) J220 , replacing .
Install the engine cover with air filter → 24 MULTIPORT FUEL INJECTION (MFI) .

Final procedures

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

Check the DTC memory.
If necessary, erase the DTC memory. Refer to Diagnostic Mode 04: Reset/delete diagnostic data .
If the DTC memory was erased, generate readiness code. Refer to Readiness Code .

End of diagnosis.