Diagnosis of ignition coils with resistance measurement

For the diagnosis of an ignition coil, you measure the electrical resistance of the ignition coil with a multimeter

Based on its electrical resistance, the function of conventional ignition coils for transistor ignition systems and electronic ignition systems electronic map ignition can be checked.

The test takes place with a multimeter while uninstalled. The electrical resistance in the primary and secondary areas is measured.

Measurement of the primary resistance

You can determine the primary resistance of an ignition coil, for example, by connecting a multimeter to Terminals 15 and 1 of the ignition coil. The following guideline values apply for most functional ignition coils:

  • Transistor ignition system: 0.5 – 2.0 Ω.
  • Electronic ignition system with electronic map ignition: 0.5 – 2.0 Ω.
  • Fully electronic ignition system (single and double spark technology): 0.3 – 1.0 Ω.

Measurement of the secondary resistance

The secondary resistance is measured directly at the high-voltage outlet. The following guidelines values apply:

  • Transistor ignition system: 8.0 – 19.0 kΩ.
  • Electronic ignition system with electronic map ignition: 8.0 – 19.0 kΩ.
  • Fully electronic ignition system (single and double spark technology): 8.0 – 15.0 kΩ.