Knock Recognition Control Limit, Checking

Knock Recognition Control Limit, Checking

If a DTC relating to "knock recognition control limit reached " is made, perform the following checks:

Work sequence

- Connect vehicle diagnostic, testing and information system (VAS 5051) => [ VAS5051, Connecting and Selecting Functions ] VAS 5051, Connecting and Selecting Functions and select vehicle system "01 -Engine electronics" in selection. Engine must be run at idle.

Display on (VAS 5051):





- Under - 1 - select diagnostic function "08 - Read measured value block".

Display on (VAS 5051):





1. Enter display group

- Enter "020" for "display group number 020" in zone - 2 - and confirm entry by pressing Q button.

Display on (VAS 5051):





- Check knock control in display zones - 1 - to - 4 -.





• The numbers displayed in display zones 1 to 4 represent the actual ignition timing retardation due to the knock control of the individual cylinders. The ignition angle retardation is carried out late in° KW (crankshaft degree).

- Exit function "08 - Read measured value block" by pressing arrow button.

Evaluation ignition angle retardation