P2318

DTC P2318

Circuit Description

The ignition system uses individual ignition coil/module assemblies for each cylinder. The engine control module (ECM) controls the individual coils by transmitting timing pulses on the ignition control (IC) circuit of each ignition coil/module to enable a spark event. The ECM monitors each IC circuit for improper voltage levels. Each ignition coil/module has the following circuits:

^ An ignition voltage circuit
^ A ground
^ An IC circuit
^ A low reference circuit

If the ECM detects a short to ground on the IC circuit of the ignition coil/module, it will set the corresponding DTC.

^ DTC P2300 for ignition coil/module 1
^ DTC P2303 for ignition coil/module 2
^ DTC P2306 for ignition coil/module 3
^ DTC P2309 for ignition coil/module 4
^ DTC P2312 for ignition coil/module 5
^ DTC P2315 for ignition coil/module 6
^ DTC P2318 for ignition coil/module 7
^ DTC P2321 for ignition coil/module 8

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The ECM detects a short to ground on the IC circuit of the ignition coil/module.

Action Taken When the DTC Sets

^ The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

^ The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Clear the MIL and the DTC with a scan tool.