Checking function

Connect V.A.G 1551 scan tool ((V.A.G 1552). 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, see VAG1551 SCAN TOOL, CONNECTING AND SELECTING ENGINE CONTROL MODULE .)

Indicated on display:

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

Fig 1: Identifying Scan Tool Display - Knock Sensor, Checking (1 Of 3)
Courtesy of VOLKSWAGEN OF AMERICA, INC.

Indicated on display:

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

Fig 2: Identifying Scan Tool Display - Knock Sensor, Checking (2 Of 3)
Courtesy of VOLKSWAGEN OF AMERICA, INC.

Indicated on display: (1 to 4 Display zones)

Fig 3: Identifying Scan Tool Display - Knock Sensor, Checking (3 Of 3)

Courtesy of VOLKSWAGEN OF AMERICA, INC.

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, see SAFETY PRECAUTIONS .

DISPLAY GROUP 28: IGNITION, KNOCK CONTROL

	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	Up To 40.0%	85.0 to 105.0 °C	Syst. OK.
	---	---	---	If the specifications are not achieved, see 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.