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 VAS5051 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-.







NOTE: 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 degrees KW (crankshaft degree).

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

Evaluation ignition angle retardation