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 failure on the IC circuit of the ignition coil/module, it will set one of the corresponding DTCs, DTC P0351 through P0358.
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 |
| • | DTC P0355 Ignition Coil 5 Control Circuit |
| • | DTC P0356 Ignition Coil 6 Control Circuit |
| • | DTC P0357 Ignition Coil 7 Control Circuit |
| • | DTC P0358 Ignition Coil 8 Control Circuit |
Conditions for Running the DTC
| • | The engine is cranking or running. |
| • | DTCs P0351-P0358 will set when 50 out of 63 engine cycles show the failure conditions. The time duration varies with engine speed. This test runs continuously. |
Conditions for Setting the DTC
The ECM detects one of the following failures on the IC circuit:
| • | 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: Engine 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 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 . 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 . 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 . 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 . 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 . 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 . 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 engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . 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 - Bank 2 or Ignition Coil Replacement - Bank 1 . Did you complete the replacement? | Go to Step 16 | -- |
15 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. 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 | |
