Misfire recognition, checking
Special tools and equipment
- VAS 5051 with VAS 5051/1
Work sequence
- Connect Vehicle Diagnostic, Testing and Information System VAS 5051 or VAG 1551. Refer to VAS 5051 vehicle diagnostic, testing and information system, connecting and selecting functions tester and select control module for engine electronics 1 by inserting address word 01. Engine must be running at idle for this test.
| Rapid data transfer HELP Select function XX |
Indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08 and press Q button to confirm input.
| Read Measuring Value Block Q Input display group number XXX |
Indicated on display
- Press buttons -0-, -1- and -4- to input "display group number 14" and press Q button to confirm input.
| Read Measuring Value Block 14 → 1 2 3 4 |
Indicated on display
- Check misfire detection.
| Display zones | ||||
| 1 | 2 | 3 | 4 | |
| Display group 014: Misfire recognition | ||||
| Display | xxx rpm | xxx % | xxx | --- |
| Display | Engine speed | Load | Total misfire | Misfire recognition |
| Range | min.: 550 RPM max.: 7200 RPM |
min.: 0 max.: 100 |
Activated Not activated |
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| Specified value | 600 to 820 rpm | xx.x % | 0 to 5 | Activated |
| --- | --- | If the specified value is not reached: Evaluation display field 3. Refer to Evaluating display groups 014, 015 and 016, Display field 3: | --- | |
If specified value is reached:
- Press → button.
| Rapid data transfer HELP Select function XX |
Indicated on display (function selection):
If specified value is not obtained:
- To switch to display group 015 press s button.
Checking misfire recognition of the individual cylinder
Display on VAS 5051:
- Check misfire recognition in display zones -1- to -4-.
| Display zones | ||||
| 1 | 2 | 3 | 4 | |
| Display group 015: Misfire recognition of cylinders 1, 2 and 3 | ||||
| Display | xxx | xxx | xxx | --- |
| Display | Number of misfires in cylinder 1 | Number of misfires in cylinder 2 | Number of misfires in cylinder 3 | Misfire recognition |
| Range | Activated Not activated |
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| Specified value | 0 | 0 | 0 | Activated |
| If nominal value is exceeded: Evaluation. Refer to Evaluating display groups 014, 015 and 016, Display field 3: | --- | |||
- To switch to display group 016 press [Back Arrow] button.
Display on VAS 5051:
- Check misfire detection in display zones -1- and -4-.
| Display zones | ||||
| 1 | 2 | 3 | 4 | |
| Display group 016: Misfire recognition of cylinder 4. | ||||
| Display | xxx | --- | ||
| Display | Number of misfires in cylinder 4 | Misfire recognition | ||
| Range | Activated Activated |
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| Specified value | 0 | Activated | ||
| If nominal value is exceeded: Evaluation. Refer to Evaluating display groups 014, 015 and 016, Display field 3: | --- | |||
- Exit function "08 - Read measured value block" by pressing ← button.
Evaluating display groups 014, 015 and 016, Display field 3:
| Display field: 3 | Possible cause | Corrective action |
| Greater than 5 |
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