Ignition Coil Primary Circuits (#2 and #4)

NAME OF CODE
Ignition Coil Primary Circuit (Circuits #2 and #4)

WHEN MONITORED
During engine cranking with battery voltage greater than 8 volts or with engine running with battery voltage greater than 12 volts, engine RPM less than 2016 and none of the coils in dwell when checked.

SET CONDITION
Peak current is not achieved with battery based dwell plus 1.5 millisecond of diagnostic offset. Takes less than 3 seconds during cranking or up to 6 seconds while running to set.

THEORY OF OPERATION
The ignition coil is supplied 12 volts from the Automatic Shutdown (ASD) relay. The ignition control module controls two primary circuits: cavity 5 controls #4 and cavity 1 controls #2. The ignition control module is supplied two signals from the powertrain control module. One signal is the dwell signal, which tells the ignition control module when to fire the coil. The dwell gate signal tells the ignition control module which coil to fire.

POSSIBLE CAUSES
- Open or shorted ignition coil driver circuit
- Open ignition coil primary
- Open ASD output circuit
- Failed ignition control module
- Open or shorted dwell signal
- Open or shorted dwell gate signal