Circuit Description
Ignition 1 voltage is supplied to the ignition coil. The engine control module (ECM) provides a ground for the ignition coil (IC) control circuits. When the ECM removes the ground path of the ignition primary coil, the magnetic field produced by the coil collapses. The collapsing magnetic field produces a voltage in the secondary coil which ignites the spark plugs. The sequencing and timing are controlled by the ECM. The ignition coil consists of the following circuits:
| • | The ignition 1 voltage |
| • | The IC 1 and 4 control |
| • | The IC 2 and 3 control |
If the ECM detects an incorrect signal in the IC circuits, DTCs P0351 or P0352 sets.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0351 Ignition Coil 1 and 4 Control Circuit |
| • | DTC P0352 Ignition Coil 2 and 3 Control Circuit |
Conditions for Running the DTC
| • | The engine is operating. |
| • | The DTCs run continuously when the above condition is met. |
Conditions for Setting the DTC
The ECM detects an open, short to ground, or short to voltage in the IC circuits.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers. |
| • | A history DTC is stored. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | DTCs can be cleared by using the scan tool. |
| • | Disconnect the ECM battery feed for more than 10 seconds. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for an open or short to ground in the ignition 1 voltage circuit of the ignition coil circuit.
-
This step tests the ignition coil. If the frequency is not within the specified range, there is a condition with the ignition control circuit or the ECM.
Step | Action | Values | 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 - Engine Controls ? | -- | Go to Step 2 | |||||||||
2 |
Did DTC P0351 or P0352 fail this ignition? | -- | Go to Step 4 | Go to Step 3 | ||||||||
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Intermittent Conditions | ||||||||
Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 9 | |||||||||
Is the frequency more than the specified value? | 3 Hz | Go to Step 7 | Go to Step 6 | |||||||||
6 | Test the appropriate ignition control circuit of the ignition coil for the following conditions:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 8 | ||||||||
7 | Test for an intermittent and for a poor connection at the ignition coil. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 | ||||||||
8 | Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 | ||||||||
9 | Repair an open or a short to ground in the ignition 1 voltage circuit of the ignition coil. Refer to Wiring Repairs . Did you complete the repair? | -- | Go to Step 12 | -- | ||||||||
10 | Replace the ignition coil. Refer to Ignition Coil Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||||
11 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||||
12 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 13 | ||||||||
13 | Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||
