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, the corresponding DTC will set.
DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- P2300 Ignition Coil 1 Control Circuit Low Voltage
- P2303 Ignition Coil 2 Control Circuit Low Voltage
- P2306 Ignition Coil 3 Control Circuit Low Voltage
- P2309 Ignition Coil 4 Control Circuit Low Voltage
- P2312 Ignition Coil 5 Control Circuit Low Voltage
- P2315 Ignition Coil 6 Control Circuit Low Voltage
- P2318 Ignition Coil 7 Control Circuit Low Voltage
- P2321 Ignition Coil 8 Control Circuit Low Voltage
CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- DTC P2300, P2303, P2306, P2309, P2312, P2315, P2318, and P2321 run continuously once the above condition is met.
CONDITIONS FOR SETTING THE DTC
The ECM detects a short to ground on the IC circuit of the ignition coil/module for more than 2 seconds.
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.
TEST
