Circuit Description
The ignition system uses individual ignition coil/module assemblies for each cylinder. The powertrain control module (PCM) 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 PCM 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 |
If the PCM detects an improper voltage level on the IC circuit of the ignition coil/module, it will set the following corresponding DTCs:
| • | DTC P0351 for ignition coil/module 1 |
| • | DTC P0352 for ignition coil/module 2 |
| • | DTC P0353 for ignition coil/module 3 |
| • | DTC P0354 for ignition coil/module 4 |
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0351 Ignition Coil 1 Control Circuit |
| • | DTC P0352 Ignition Coil 2 Control Circuit |
| • | DTC P0353 Ignition Coil 3 Control Circuit |
| • | DTC P0354 Ignition Coil 4 Control Circuit |
Conditions for Running the DTC
| • | The engine is running. |
| • | DTC P0351-P0354 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The PCM detects one of the following failures on the IC circuit of the ignition coil/module for less than 1 second.
| • | An open |
| • | A short to ground |
| • | A short to voltage |
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. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Did the DTC fail this ignition? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections |
3 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 4 |
4 | Probe the affected IC circuit at the harness connector with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 6 | Go to Step 5 |
5 |
Does the cylinder misfire transfer with the suspect ignition coil/module? | Go to Step 9 | Go to Step 8 |
6 | Test the IC circuit of the ignition coil/module for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 10 |
7 | Test the IC circuit of the ignition coil/module for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 10 |
8 | Test the IC circuit of the ignition coil/module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 10 |
9 | Test for an intermittent and for a poor connection at the ignition coil/module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 11 |
10 | Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
11 | Replace the ignition coil/module. Refer to Ignition Coil Replacement . Did you complete the replacement? | Go to Step 13 | -- |
12 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 13 | -- |
13 |
Did the DTC fail this ignition? | Go to Step 3 | Go to Step 14 |
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |
