摘要 |
An apparatus for determining component fault conditions associated with a capacitive discharge ignition system for an internal combustion engine includes a number of AC coupling circuits connected to a spark detection circuit, wherein the combination is responsive to a corresponding number of primary coil voltage signals to produce digital pulses indicative of reflected spark events from the various secondary coils to the respective primary coils of the ignition system. A number of level shifting circuits are also included and provide a pulse width circuit with a corresponding number of level-shifted primary coil voltage signals. A pulse width circuit is responsive to the number of level-shifted primary coil voltage signals to produce appropriate digital pulses timed to match the non-zero voltage times of the various primary coil voltage signals. A signal processing circuit is responsive to the digital signals produced by the spark detection circuit and the pulse width circuit to determine spark breakdown voltage, shorted ignition coils, worn ignition plugs, shorted ignition plugs, ignition control module faults and external arcing conditions. These faults are communicated to a service technician via a display and/or by logging such faults in memory.
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