Resistance Checks

Circuit diagram for ignition coil in breakerless ignition distribution.
A. Piloting of primary coil in ignition coil of DME
B. Ignition coil
C. Ground connection of secondary coil
D. Measuring resistance which is installed in ground wire shared by ignition coils. The measuring resistance is required for fault recognition in the secondary circuit of the ignition coils. The fault is stored in the fault memory of the DME control unit.

RESISTANCE CHECK:
- Resistance check between pins 1 and pin 15.
- Primary coil: Nom. value 0.4 - 0.8 ohm
- Secondary coil not registering on measuring instrument.




Pin allocation on ignition coil connector:
1. Terminal 15
2. Terminal 4a
3. Terminal 1

VISUAL INSPECTION OF THE IGNITION COIL:
- Check cast compound of primary coil carrier for hairline cracks. If gray material has emerged around the edges of the coil carrier, this indicates the presence of a defective ignition output stage in the DME control unit.