Audi Workshop Service and Repair Manuals > A4 Mk1 > Power unit | Motronic injection and ignition system (6 cyl. turbo) | Ignition system, glow plug system | Checking ignition system

Motronic injection and ignition system (6 cyl. turbo)

Checking ignition system

Testing misfire detection

Note:

Misfire detection is only active on vehicles that conform to emission standard EU III.

Test sequence

‒ Connect up vehicle diagnostic, testing and information system VAS 5051 or fault reader V.A.G 1551 and select engine electronics control unit with "Address word" 01 .
For this purpose, the engine must be running at idle speed

→ When adjacent display appears:

Rapid data transfer HELP

Select function XX

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

→ When adjacent display appears:

Reading measured value block Q

Enter display group number XXX

‒ Press keys 0, 1 and 4 for "display group number 14" and confirm entry with Q key.

→ When adjacent display appears:

Read measured value block 14 ⇒

1 2 3 4


	Display zones
	1	2	3	4
Display group 014: Misfire detection
Display	xxx rpm	xxx %	xxx	---
Display	Engine speed	Load	Total misfires	Misfire detection
Range	min.: 750 rpm max.: 6800 rpm	min.: 0 max.: 175		activated blocked
Specified value	750...850 rpm	15.0...22.0 %	0...15	activated
Note:	---	---	If specified value is not attained: Evaluation, display zone 3 => Page 28-53.	---

If specified value is attained:

→ Display readout (function selection):

Rapid data transfer HELP

Select function XX

Evaluation display group 14, display zone 3

Display zone: 3	Possible causes of fault	Fault remedy
higher than 15	- Defective spark plug - Defective spark plug connector - Ignition coil or output stage	- Test spark plugs and ignition wiring Check ignition coils => Page 28-10
	- Injector defective - Poor compression on one or more cylinders	- Check injectors Check compression

The measured value blocks that indicate the misfires of the individual cylinders are as follows:


	Display zones
	1	2	3	4
Display group 015: Misfire detection 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 detection
Range				activated blocked
Specified value	0...15	0...15	0...15	activated
Note:	If specified value is not attained: Evaluation .	If specified value is not attained: Evaluation .	If specified value is not attained: Evaluation .	---

Note:

Note that misfire detection is only displayed on vehicles that conform to emission standard EU III .


	Display zones
	1	2	3	4
Display group 016: Misfire detection of cylinders 4, 5 and 6
Display	xxx	xxx	xxx	---
Display	Number of misfires in cylinder 4	Number of misfires in cylinder 5	Number of misfires in cylinder 6	Misfire detection
Range				activated blocked
Specified value	0...15	0...15	0...15	activated
Note:	If specified value is not attained: Evaluation .	If specified value is not attained: Evaluation .	If specified value is not attained: Evaluation .	---

Note:

Note that misfire detection is only displayed on vehicles that conform to emission standard EU III .

Evaluation of measured value blocks 15 and 16

Display zones:1/2/3	Possible causes of fault	Fault remedy
higher than 15	- Defective spark plug - Defective spark plug connector - Ignition coil or output stage	- Test spark plugs and ignition wiring Check ignition coils => Page 28-10
	- Injector defective - Poor compression on one or more cylinders	- Check injectors Check compression

Audi Workshop Service and Repair Manuals