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 corresponding DTC.
| • | 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 |
Conditions for Running the DTC
The engine is running.
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-Engine Controls? | Go to Step 2 | |
2 |
Did the DTC fail this ignition? | Go to Step 3 | Go to Intermittent Conditions |
3 |
Does the test lamp illuminate? | Go to Step 8 | Go to Step 4 |
4 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 5 |
5 | Probe the affected low reference circuit at the harness connector with a test lamp that is connected to battery voltage. Does the test lamp illuminate? | Go to Step 6 | Go to Step 9 |
6 |
Does the cylinder misfire transfer with the suspected ignition coil/module? | Go to Step 12 | Go to Step 10 |
7 | Test the IC circuit of the ignition coil/module for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 13 |
8 | Test the IC circuit of the ignition coil/module for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 13 |
9 | Test the low reference circuit of the ignition coil/module for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 13 |
10 | Test the IC circuit of the ignition coil/module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 11 |
11 | Test the low reference circuit of the ignition coil/module for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 13 |
12 | 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 in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 14 |
13 | 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 in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 15 |
14 | Replace the ignition coil/module. Refer to Ignition Coil Replacement . Did you complete the replacement? | Go to Step 16 | -- |
15 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | Go to Step 16 | -- |
16 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 17 |
17 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |
