Knock Control, Checking

Special tools and equipment
- VAG 1551/1552 Scan Tool using VAG 1551/3 adapter cable
- VAG 1598/18 Test Box
- Fluke 83 multimeter (or equivalent)
- VW 1594 Adapter kit
- Wiring diagram

Test sequence
- Connect VAG 1551 (VAG 1552) Scan Tool. Refer to Scan Tool Testing/VAG 1551 Scan Tool. Testing and Inspection
- With engine idling, press buttons -0- and -1- to select "Engine electronics" address word 01.

Display will appear as shown


Rapid data transfer HELP
Select function XX


- Press buttons -0- and -8- to select "Read measuring value block".
- Press -Q- button to enter selection.

Display will appear as shown


Read measuring value block HELP
Input Display group number XXX


- Press buttons -0-, -4- and -5- to select "Display group number 45" (Cyl. 1 to 4) or:
- Press buttons -0-, -4- and -6- to select "Display Group number 46 "(Cyl. 5 and 6).
- Press -Q- button to enter selection.

Display will appear as shown (1 to 4 = Display fields)


Read measuring value block 45 ->
1 2 3 4


NOTE: Check must be carried out during road test because knock control is only active when engine load exceeds 3 ms.


- Road test vehicle and observe knock control specifications on display (2nd person required). During road test, engine coolant temperature must exceed 80 °C.

When the above temperature is reached, the following operating conditions must be attained several times:
- Closed throttle
- Partially open throttle
- Wide open throttle
- Overrun
- At wide open throttle, engine rpm must exceed 3500

Display Group 45:

- Read-out Readiness code. Refer to Monitors, Trip and/or Drive Cycle (Readiness Codes)/Readiness Code Checking. Testing and Inspection

If DTC memory has been erased:
- Create Readiness code. Refer to Monitors, Trip and/or Drive Cycle (Readiness Codes)/Readiness Code Generating Testing and Inspection
- Press -> button.
- Press buttons -0- and -6- to select "End output".
- Press -Q- button to enter selection.


Evaluating Display group 45 and 46