Knock sensors, checking

WARNING: This page is about a different car, the 2001 Volkswagen Jetta, 2001 Volkswagen Golf, 2000 Volkswagen Jetta, 2000 Volkswagen Golf, and 2000 Volkswagen GTI. However, it is still accessible from the selected car via links, so may be relevant.

Notes:

It is extremely important to keep to the tightening torque of 20 Nm to ensure the knock sensors perform perfectly.
Only gold-plated contacts may be used when servicing the knock sensor connector contacts.

Special tools and equipment

Test box VAG 1598/31
Hand multimeter VAG 1526 or multimeter VAG 1715
Adapter set VAG 1594
Wiring diagram

Test conditions

On Board Diagnostic (OBD) must have recognized a malfunction on one or both knock sensors.

Checking resistances and wiring

Fig 1: 3-Pin Connector Separated From Knock Sensor 1 -G61-

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Separate 3-pin connector to Knock sensor (KS) 1 -G61- -1-.
Measure resistance between contacts 1 + 2, 1 + 3 and 2 + 3 at connections to knock sensors.

Specification ∞ Ω

Fig 2: 3-Pin Connector Separated From Knock Sensor 2 -G66-

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Separate 3-pin connector to Knock sensor (KS) 2 -G66- -1-.
Measure resistance between the contacts 1 + 2, 1 + 3 and 2 + 3 at connections to knock sensors.

Specification ∞ Ω

If the specification is not obtained:

Replace knock sensor(s)

If the specification is obtained:

Fig 3: Identifying Test Box V.A.G 1598/31 Connected To Control Module Wiring Harness

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Connect test box VAG 1598/31 to control module wiring harness. Engine control module remains disconnected.
Check wiring between test box and 3-pin connector for open circuit using wiring diagram.

	-G61-:	-G66-:
Contact 1 + socket	106	107
Contact 2 + socket	99	99
Contact 3 + socket	108	108
Wire resistance: Max. 1.5 Ω

Additionally check wires for short to one another.

If no wiring fault is detected:

Loosen knock sensor and tighten again to 20 Nm.
Test drive vehicle.

During the road test the following operating conditions must be fulfilled:

Coolant temperature must exceed 80 ° C.
When the temperature is reached, the operating conditions

Idling

Part throttle

Wide Open throttle

Overrun

must be attained several times.

At Wide Open throttle the speed must exceed 3500 RPM.

Again check control module DTC memory.

If the malfunction is still present:

Replace knock sensor(s).