Checking function

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Connect VAG1551 scan tool (VAG1552). Start engine and select "Address word" 01 of engine control module. Engine must be running at idling speed. (Connecting scan tool and selecting engine control module → VAG1551 scan tool, connecting and selecting engine control module .)

Indicated on display:

Rapid data transfer HELP
Select function XX

Press keys 0 and 8 for function "Read measured value block" and confirm entry with Q key.

Indicated on display:

Read measured value block
Input display group number XXX

Press keys 0 , 2 and 8 for "Display group number 28" and confirm entry with Q key.

Indicated on display: (1 to 4 = Display zones)

Read measured value block 28 →
1 2 3 4

NOTE:

Checking the knock sensors must be performed during a test drive because the diagnosis of the knock sensors is not activated until the engine speed exceeds 1800 rpm and the engine is loaded by more than 40%.

Perform a test drive and check knock control specifications on display (display zone 4).

Observe the valid safety precautions when performing a test drive → Safety precautions .

	Display zones
	1	2	3	4
Display group 28: Ignition, knock control
Display	xxxx rpm	xxx.x%	xxx.x ° C	Test OFF/Test ON Syst. OK. Syst. n. OK.
Indicated	Engine speed (in steps of 40)	Engine load	Coolant temperature	Diagnosis condition and Diagnosis result
Working range	0 to 6800 rpm	0.0 to 150.0%	-40.0 to 110.0 ° C	---
Specification	at least 1800 rpm	> 40.0%	85.0 to 105.0 ° C	Syst. OK.
	---	---	---	If the specifications are not achieved , Continuation

If the specification is attained:

Press → key.
Press keys 0 and 6 for function "End output" and confirm entry with Q key.
Switch ignition off.