Knock sensor and knock sensor control, checking: Checking

Connect VAG1551/1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with engine running at idle). See VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01 .

Indicated on display

Fig 1: Checking Knock Sensor And Knock Sensor Control Using VAG Scan Tool (1 Of 3)

Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.

Indicated on display

Fig 2: Checking Knock Sensor And Knock Sensor Control Using VAG Scan Tool (2 Of 3)

Press buttons corresponding to following display group numbers and press -Q- button to confirm input.
- 022: Display group 22, for cylinders 1 and 2
- 023: Display group 23, for cylinders 3 and 4
- 024: Display group 24, for cylinders 5 and 6

Indicated on display (1-4 - display groups)

Fig 3: Checking Knock Sensor And Knock Sensor Control Using VAG Scan Tool (3 Of 3)

NOTE: The test must be carried out during a road test because the knock sensor system is only active with engine speed greater than 2600 RPM and engine load greater than 3 ms.

Road test and compare display with specified values for knock sensor system in display field 1-4.

WARNING: A second technician is required to operate the VAG1551 scan tool during the road test. See SAFETY PRECAUTIONS .

DISPLAY GROUP 22 KNOCK CONTROL

Display fields

Display group 22 ⁽¹⁾: Knock control

Display

xxx RPM

xx.xx ms

xx.x°

Display

Engine speed
(in 40 RPM steps)

Engine load

Ignition angle correction 1

Ignition angle correction 2

Work range

0-6800 RPM

0.00-12.75 ms

0.0-12.0° (crankshaft)

Specified Value

... RPM (test drive)

... ms (test drive)

0.0-10.0° (crankshaft)

If displayed values are NOT OK, go to EVALUATION OF DISPLAY GROUPS 22, 23 AND 24 .

⁽¹⁾	Display also valid for display groups 23 (cyls. 3 and 4) and 24 (cyls. 5 and 6).

If displayed values are OK:

Press --> button.
Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
Check readiness code. See READINESS CODE .
If Diagnostic Trouble Code (DTC) memory has been erased, or ECM has been disconnected, generate new readiness code. See READINESS CODE, CHECKING .