Knock Sensor 1, Checking: Notes

The following procedure is used to diagnose all Knock Sensors --.

Special tools and workshop equipment required

Test requirements

The mounting bolt of Knock Sensor (KS) 1 -G61- 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

-- 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.

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

Fig 1: Electrical Harness Connectors

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Switch the ignition ON.

-- Using a multimeter, Check the Knock Sensor (KS) 1 -G61- electrical harness connector terminals 1 to 2 for voltage.

Specified value: about 5.0 V

-- Switch the ignition Off.

Continue test according to the following table:

Value	Cause	Test
If the specified value was not obtained:	Open or shorted circuit	Checking wiring
If the specified value was obtained:	Check reference signal circuit	Check reference signal