Checking function
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 Volkswagen Jetta, 2002 Volkswagen GTI, 2001 Volkswagen Jetta, 2001 Volkswagen GTI, and 2000 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.
- 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.