Modes of Operation

During normal operation, the engine control module (ECM) controls all ignition functions. If either the crankshaft position (CKP) or the camshaft position (CMP) sensor signal is lost, the engine will continue to run because the ECM will default to a limp-home mode using the remaining sensor input. Each coil is internally protected against damage from excessive voltage. Diagnostic trouble codes are available to accurately diagnose the ignition system with a scan tool.