Knock Sensor 1

WARNING: This page is about a different car, the 2009 Audi S8, 2008 Audi S8, and 2007 Audi S8. However, it is still accessible from the selected car via links, so may be relevant.

The following procedure is used to diagnose Knock Sensor (KS) 1 G61 which is controlled by Motronic Engine Control Module (ECM) J623.

Special tools, testers and auxiliary items required

Multimeter.
Wiring diagram.

Test requirements

The mounting bolt of Knock Sensor (KS) 1 G61 tightened to 20 Nm.
The Motronic 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 (GND) connections between engine/transmission/chassis OK.
Ignition switched off.

Procedure

Fig 1: Removing Rear Engine Cover

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Remove the front engine cover - 1 -.

Fig 2: Disconnecting Intake Flap Motor Electrical Harness Connector

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Disconnect the orange Knock Sensor (KS) 1 G61 electrical harness connector - 9 -.

Checking internal resistance

Fig 3: Identifying Knock Sensor Terminals

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Using a Multimeter, check the Knock Sensor (KS) 1 G61 terminals 1 to 2 for an internal short.

Specified value: ∞ (Infinity).

If the specified value was not obtained:

Replace Knock Sensor (KS) 1 G61. Refer to → .

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 → .

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

Remove the Motronic Engine Control Module (ECM) J623. Refer to → .

Fig 4: Identifying 3-Pin Connector Terminals 1 & 3

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Using a Multimeter, check the Knock Sensor (KS) 1 G61 electrical harness connector to the Motronic Engine Control Module (ECM) J623 electrical harness connector T60a for an open circuit.

Knock Sensor (KS) 1 G61 electrical harness connector terminals	Motronic Engine Control Module (ECM) J623 electrical harness connector T60a terminals or test box sockets
1	39
2	54
3	52 (Shield)

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 Knock Sensor (KS) 1 G61. Refer to → .

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

Replace the Motronic Engine Control Module (ECM) J623. Refer to → .
Assembly is performed in the reverse order of removal.

Final procedures

After 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 - Erase DTC Memory .
If the DTC memory was erased, generate readiness code. Refer to Readiness Code .

End of diagnosis.