Checking function
- Connect Scan Tool (ST) VAG 1551 or mobile scan tool VAG 1552. Start engine and press buttons - 0 - and - 1 - to select "Engine Electronics" address word 01 (engine must be running at idle speed) → Scan Tool (ST) VAG 1551 , connecting and selecting functions .
Indicated on display:
| Rapid data transfer HELP Select function XX |
- Press buttons - 0 - and - 8 - to select "Read Measuring Value Block" function 08, and press - Q - button to confirm input.
Indicated on display:
| Read Measuring Value Block Input display group number XXX |
- Press buttons - 0 - , - 2 - and - 8 - to input display group number 28 - 028 - , and press - Q - button to confirm input.
Indicated on display: (1-4 = display fields)
| Read Measuring Value Block 28 -> 1 2 3 4 |
NOTE:
- Checking the knock sensors must be performed during a road test because the diagnostic of the knock sensors is not activated until the engine speed exceeds 2000 rpm and the engine is under more than a 40% load.
- Road test vehicle and check knock control Specified values on display (display fields 3 and 4).
Observe the valid safety precautions when performing a road test → Safety precautions .
| Display fields | ||||
| 1 | 2 | 3 | 4 | |
| Display group 028: 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 | 0-6800 RPM | 0.0-100.0 % | -40.0-140.0 ° C | --- |
| Specified value | at least 2000 RPM | > 40.0 % | 85.0-105.0 ° C | Syst. OK. |
| --- | --- | --- | If the specifications are not achieved → Continuation, | |
If the specification is obtained:
- Press → button.
- Press buttons - 0 - and - 6 - to select "End Output" function 06 and press - Q - button to confirm input.
- Switch ignition off.