Note. Each DTC represents a different control module. See DTC DEFINITIONS under SELF-DIAGNOSTIC SYSTEM.
Circuit Description
Ignition signal and ignition fail-safe signal provide crucial information in control of ignition system timing, injector timing and fail-safe activation. Based on initial timing calculated by crankshaft and camshaft sensor signals, PCM sends an ignition signal to ignition control module (located in ignition coil) and uses it as a reference point to determine ignition dwell.
A circuit within ignition control module controls ignition dwell and spark period by controlling power transistor switch on and off. After spark has occurred, ignition control module sends an ignition fail-safe signal to PCM, confirming an ignition event has taken place. If fail-safe signal is not received by PCM, fail-safe mode is activated and fuel injector operation is ceased to prevent catalytic converter damage. DTC P1300 will set when no ignition fail-safe signal is received by PCM for 2 consecutive ignition cycles during engine operation. When DTC sets, MIL will illuminate. PCM will record operating conditions at time of diagnostic failure and store information in freeze frame buffer. PCM will enter Fail-Safe Function and begins fuel cut mode operation (terminates fuel delivery).