Ignition circuit monitoring

The firing circuit is monitored on the basis of the current in the primary coil of the ignition coil. The current must be within certain values during certain time thresholds for switching on. The following are monitored in the ignition diagnosis:

• Primary power circuit of the ignition coil
• Wiring harness for the ignition
• Secondary power circuit of the ignition coil with spark plug
• Duration of spark combustion

The following faults can be detected by the ignition-circuit monitoring:

• Short circuit on the primary side of the ignition coil
• Short circuit on the secondary side of the ignition coil
• Spark plug
• Break in wiring of the activation
• Defective ignition output stages

The following cannot be detected:

• Sporadic faults, such as loose contacts or activation line
• Flashovers in the high-tension circuit parallel to the spark gap without the formation of a coil short circuit