Circuit Description
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 1 voltage is directly supplied to the ignition coil from the ECM. The IC circuits are directly connected to the ECM from the ignition coil. 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 ignition is ON or the engine is operating. |
| • | DTCs P0351 and P0352 run continuously once the above condition is met. |
Conditions for Setting the DTC
The ECM detects an incorrect signal in the IC circuits for 3 seconds.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 4 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. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if there is a fault within an ignition coil circuit.
-
This step tests the ignition coil. If the frequency is 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 Controls Connector End Views | ||||||||||||
1 | Did you perform the Diagnostic System Check - Engine Controls ? | -- | Go to Step 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 | ||||||||
Is the frequency more than the specified value? | 3 Hz | Go to Step 6 | Go to Step 5 | |||||||||
5 | Test the appropriate ignition control circuit of the ignition coil for the following conditions:
Refer to Testing for Short to Ground in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 7 | ||||||||
6 | 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 in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 | ||||||||
7 | Test for an intermittent and for a poor connection at the ECM. 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 10 | Go to Step 9 | ||||||||
8 | Replace the ignition coil. Did you complete the replacement? | -- | Go to Step 10 | |||||||||
9 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 10 | |||||||||
10 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 11 | ||||||||
11 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||
