Ignition Coil: Testing and Inspection

Checking Ignition Coils (Secondary Coil)

Special tools required:
- 12 7 040
- 12 7 041
- 12 7 042
- 12 7 043
- 12 7 045
- 12 7 046
- 12 7 050

Carry out secondary voltage check using test adapter 12 7 040.







IMPORTANT: Observe safety precautions. Switch off ignition.

NOTE: The following checks can be carried out with the adapter kit:
- Secondary voltage check
- Comparison between ignition coils from different manufacturers
- Ignition coil faults
- Spark plug faults
- Injection system faults







Connect special tool 12 7 043 (connecting cable) to special tool 12 7 041 (single adapter).







NOTE: Checks on engines with single-spark ignition coils:
Special tool 12 7 041 (single adapter) in conjunction with special tool 12 7 045 for fitting onto ignition coil.

Remove cover for ignition coils.







Version with single-spark ignition coils:
Mount special tool 12 7 041 on ignition coils and connect to special tool 12 7 043 .







Connect DIS Tester with RZV connecting lead to last test adapter (RZV = static ignition distribution).
Connect trigger pliers of DIS tester to feed line on ignition coil of 1st cylinder.
- Select "Measurement".
- Select "Preset measurements".

Subsequent procedure in accordance with DIS instructions.







Version with rod-type ignition coils:
Unlock plug on rod-type ignition coil and disconnect.
Remove rod-type ignition coil, connect special tool 12 7 050 (adapter cable) to spark plug and ignition coil, connect ignition coil to engine wiring harness.
Carry out measurements following DIS instructions.







Version with ignition coil block:
Raise cover on ignition coil block slightly and fit special tool 12 7 046.
Connect special tool 12 7 046 to adapter cable 12 7 042 and then to Tester.

NOTE: The adapter cable 12 7 042 is located in the case of the adapter kit 12 7 040.

Follow instructions for troubleshooting with aid of adapter kit:
- Normal oscillogram MG12
- Ignition coil comparison MG12
- Ignition coil fault MG12
- Spark plug fault MG12
- Further fault patterns MG12
- Fault at injection system MG12