Knock Sensor: Testing and Inspection

Special Tools, Testers And Auxiliary Items
- VAG 1551/1552 Scan Tool With VAG 1551/3 Adapter Cable
- VAG 1598/18 Test Box
- Multimeter (fluke 83 Or Equivalent)
- Connector Test Kit Vw 1594
- Wiring Diagram

Test sequence
- Connect VAG 1551 scan tool and select "Engine Electronics" address word 01. When doing this the engine must be running at idle speed.

Indicated on display

Rapid data transfer HELP
Select function XX

- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08 and press -Q- button to confirm input.

Indicated on display

Read Measuring Value Block HELP
Input display group number XXX

- Press buttons -0-, -4- and -5- to input display group 045 and press -Q- button to confirm input.

Indicated On Display (1-4 Display Fields)

Read Measuring Value Block 45-->
1 2 3 4


NOTE: The check must be carried out during a test drive as knock control is not active with an engine load exceeding 3 ms.


- Perform test drive and observe specification for knock control on display (Second Technician Necessary).




Display Group 045: Knock Control

- Read the readiness code. If DTC memory has been erased, repair must be verified via appropriate display group: Readiness code, creating.
- press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.




Evaluating Display Group 045

Continuation




- Disconnect blue 3-pin connector -2-from Knock Sensor (KS) 1 -G61- -1-.
- Connect multimeter with test leads from VW 1594 to measure resistance between terminals 1 and 2, 1 and 3, and 2 and 3 on knock sensor connector.
Specification: Infinite Ohms

If the specification is attained:




- Connect VAG 1598/18 Test Box To ECM Wiring Harness.





- Check wiring between test box and 3-pin connector for open circuit according to wiring diagram.
- Terminal 1 and test box socket 34
- Terminal 2 and test box socket 33
- Terminal 3 and test box socket 56
Resistance: Max. 1.5 ohms
- Additionally check wires for short to one another.
- Terminal 3 and test box socket 34
- Terminal 3 and test box socket 33
- Terminal 2 and test box socket 34
Specification: Infinite ohms

If no wiring malfunction is detected:
- Loosen knock sensor and tighten again to 20 Nm (15 ft lb).

If the malfunction is still present (malfunction again in Diagnostic Trouble Code memory):
- Replace Knock Sensor 1 -G61-.
- Read the readiness code.If DTC memory has been erased, repair must be verified via appropriate display group: Readiness code, creating.