Circuit Description
There are 3 dual-tower ignition coils integrated with the ignition control module (ICM). The ICM contains coil driver circuits that operate the 3 coils. The ICM wiring includes the following circuits:
| • | An ignition 1 voltage circuit |
| • | A ground circuit |
| • | An ignition coil 1 control circuit |
| • | An ignition coil 2 control circuit |
| • | An ignition coil 3 control circuit |
| • | A low reference circuit |
The powertrain control module (PCM) controls each ignition coil by transmitting timing pulses to the ICM on each of the ignition coil control circuits to enable properly timed spark events. The ignition coil 1 controls spark for cylinders 1 and 4. The ignition coil 2 controls spark for cylinders 2 and 5. The ignition coil 3 controls spark for cylinders 3 and 6.
If the PCM detects an incorrect voltage on any of the ignition coil control circuits, the corresponding DTC sets.
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 |
Conditions for Running the DTC
| • | The engine is cranking or running. |
| • | The DTCs run continuously when the above conditions are met. |
Conditions for Setting the DTC
The PCM detects an incorrect voltage in an ignition coil control circuit for 90 out of 100 engine cycles.
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 Powertrain Control Module 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 |
Is the frequency within the specified range? | 3-20 Hz | Go to Step 5 | Go to Step 4 | ||||||
4 | Measure the frequency between the ignition coil control circuit of the ICM 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 control circuit? | -- | Go to Step 8 | Go to Step 10 | ||||||
6 | Test the ignition coil control circuit of the ICM for the following conditions:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
7 | Test the low reference circuit of the ICM for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
8 | Test the ignition coil control circuit of the ICM for high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 9 | ||||||
9 | Test the low reference circuit of the ICM for high resistance. Refer to Circuit Testing and Wiring Repairs . 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 ICM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . 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 powertrain control module (PCM). Refer Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 | ||||||
12 | Replace the ICM and coil assembly. Refer to Ignition Coil Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
13 | Replace the PCM. Refer to Control Module References 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? | -- | System OK | |||||||
