Knock Control Stop, Checking

Knock Control Stop, Checking

If a malfunction entry relating to "knock control stop reached" is made, perform the following checks:

Special tools and equipment







- VAS5051 with VAS5051/1

Test sequence
- Connect testing and information system VAS5051 and select vehicle system "01 - Engine electronics" in selection. Engine must be running at idling speed.







Display on VAS5051:
- Under -1- select diagnostic function "08 - Read measured value block".







Display on VAS5051:
1. Enter display group max. input value = 255
- Enter "020" for "display group number 020" in zone -2- and confirm entry by pressing -Q- button.







Display on VAS5051:
- Check indication in display fields -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 CA (crankshaft degrees).

- To change to display group 021, press s button.







Display on VAS5051:
- Check indication in display fields -1- and -2-.







NOTE: The numbers displayed in display zones 1 and 2 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 CA (crankshaft degrees).

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

Evaluation of ignition angle retardation.