Ignition Coil: Testing and Inspection
On-vehicle service procedureVoltage check
1. Disconnect negative battery cable.
2. Disconnect ignition coil connector.
3. Turn ignition switch to "ON"
4. Measure voltage between terminal ECU and B+ at ignition coil connector.
5. It no voltage, check main fuse, ignition switch and wire harness.
Resistance check
1. Using an ohmmeter, check resistance of primary coil. Connect one lead of ohmmeter to positive (+) terminal and other lead to each negative (-) terminal. If not within specification, replace coil. Remember that unit has two coil assemblies, so both must be checked.
2. Using an ohmmeter, check resistance of the secondary coil. If not within specification, replace coil. Remember that you must check resistance of both top and bottom secondary coil. If one is out of specification replace the whole unit.