Enhanced Ignition System

Used on the 4.3L, 5.0L, 5.7L and 7.4L engines, the enhanced ignition system consists of the VCM, distributor, ignition coil driver module, ignition coil and camshaft position sensor. Ignition control and by-pass functions are controlled by the VCM controller.

• Crankshaft Position (CKP) Sensor
  
  CKP sensor is located in the front engine cover. Air gap between sensor and target wheel is preset and is not adjustable. Target wheel has 3 slots 60° apart and is keyed to the crankshaft. Rotation of target wheel created a change in the magnetic field of the sensor which results in an induced voltage pulse. One crankshaft revolution will result in 3 pulses (3X signal). Based on these pulses, VCM is able to determine crankshaft position and engine speed. VCM will then activate the fuel injector and provide spark to distributor.
• Distributor
  
  Distributor assembly contains the Camshaft Position (CMP) sensor, cap, rotor and shaft. A Diagnostic Trouble Code (DTC) will set when distributor is installed a tooth off in relation to the camshaft. Distributor is not serviceable.
• Camshaft Position (CMP) Sensor
  
  CMP sensor is similar to CKP sensor. CMP sensor provides one pulse (1X signal) per camshaft revolution. VCM uses this signal in conjunction with the crankshaft position to determine which cylinder(s) are misfiring.
• Ignition Coil Driver Module
  
  Module is mounted next to coil. VCM signals the ignition coil driver to turn on primary current to the ignition coil by pulling the IC line high (4 volts). The ignition control driver turns the primary current on and off by applying and removing ground to primary winding. Module does not have a back-up function that would allow engine to run if IC signal is lost.