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 an open on the IC circuit of the ignition coil/module, it will set the corresponding DTC P0351-P0358.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0351 for Ignition Coil 1 Control Circuit |
| • | DTC P0352 for Ignition Coil 2 Control Circuit |
| • | DTC P0353 for Ignition Coil 3 Control Circuit |
| • | DTC P0354 for Ignition Coil 4 Control Circuit |
| • | DTC P0355 for Ignition Coil 5 Control Circuit |
| • | DTC P0356 for Ignition Coil 6 Control Circuit |
| • | DTC P0357 for Ignition Coil 7 Control Circuit |
| • | DTC P0358 for Ignition Coil 8 Control Circuit |
Conditions for Running the DTC
| • | The ignition is ON. |
| • | DTC P0351-P0358 runs continuously once the above condition is met. |
Conditions for Setting the DTC
The ECM detects an open 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. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Engine Control Module Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Intermittent Conditions |
3 |
Is the frequency within the specified range? | 3-20 Hz | Go to Step 5 | Go to Step 4 |
4 | Measure in DC Hertz between the IC circuit of the ignition coil/module and a good ground with a DMM. Is the frequency within the specified range? | 3-20 Hz | Go to Step 7 | Go to Step 6 |
5 |
Does the cylinder misfire transfer with the suspected ignition coil/module? | -- | Go to Step 10 | Go to Step 8 |
6 | Test the IC 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 14 | Go to Step 11 |
7 | 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 14 | Go to Step 11 |
8 | Test the IC 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 14 | Go to Step 9 |
9 | 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 14 | Go to Step 11 |
10 | 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 14 | Go to Step 12 |
11 | Test for an intermittent and for a poor connection at the engine control module (ECM). Refer Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 |
12 | Replace the ignition coil/module. Refer to Ignition Coil Replacement - Bank 1 or Ignition Coil Replacement - Bank 2 . Did you complete the replacement? | -- | Go to Step 14 | -- |
13 | Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
14 |
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Step 15 |
15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
