For 1990-2009 cars

### Circuit Description

The ignition system on this engine uses individual ignition coils and ignition control (IC) circuits for each cylinder. The engine control module (ECM) controls the ignition system operation. The ECM controls each coil using the IC circuits. The ECM commands the IC circuit low when a spark event is requested. Each ignition coil is supplied the following circuits:

• | The IC circuit

• | The ignition 1 voltage circuit

• | Two ground circuits

The sequencing and timing are ECM controlled. If the ECM detects the ignition control circuit is open, this 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

• | DTC P0354 Ignition Coil 4 Control Circuit

• | DTC P0355 Ignition Coil 5 Control Circuit

• | DTC P0356 Ignition Coil 6 Control Circuit

### Conditions for Running the DTC

• | The engine is running.

• | The engine speed is between 600-5,000 RPM.

• | The ignition voltage is between 10-18 volts.

• | DTCs P0351, P0352, P0353, P0354, P0355 and P0356 run continuously once the above conditions are met and the crankshaft revolves 20 times.

### Conditions for Setting the DTC

• | The ECM detects an open in the IC circuit.

• | The condition is present for more than 4 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 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.

### Diagnostic Aids

• | Use the J 35616-A/BT-8637 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.

• | The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Front of Vehicle/Engine Compartment Component Views.

• | Inspect the ignition coils for aftermarket devices. An aftermarket device connected to the ignition coil circuits, may cause this DTC to set.

• | For an intermittent condition, refer to Intermittent Conditions.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step determines if there is a condition with an ignition coil.

2. This step tests the ignition control circuit of the ignition coil. If the frequency is not within the specified range, there is a condition with the ignition control circuit or the ECM.

3. This step tests the ignition 1 voltage supply to the ignition coil.

4. This step tests the ground circuits of the ignition coil. A high resistance in one of the ground circuits will cause a condition. Repair the ground circuits if the resistance is more than the specified value.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Engine Controls Schematics Connector End View Reference: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Start the engine.
2. Raise the engine speed above the specified value.
3. Observe the DTC Info. with a scan tool.

Does DTC P0351-P0356 fail this ignition?

700 RPM

Go to Step 4

Go to Step 3

3 |

1. Observe the Freeze Frame/Failure Records for this DTC.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 |

1. Turn OFF the engine.
2. Disconnect the appropriate ignition coil electrical connector.
3. Start the engine.
4. Measure the frequency at the ignition control circuit using the DMM set to the DC Hertz scale. Refer to Measuring Frequency.

Is the frequency within the specified range?

3-20 Hz

Go to Step 6

Go to Step 5

5 | Test the appropriate ignition control circuit for an open. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 9
6 |

1. Turn the ignition switch to ON position, with the engine OFF.
2. Probe the ignition 1 voltage circuit of the ignition coil with a test lamp connected to the engine control module (ECM) housing. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 10

7 | Measure the resistance of both ground circuits between the ignition coil connector and the ECM housing, with a DMM. Refer to Circuit Testing. Is the resistance less than the specified value? | 5 Ω | Go to Step 8 | Go to Step 11
8 | 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 14 | Go to Step 12
9 | 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 14 | Go to Step 13
10 | Repair the open in the ignition 1 voltage circuit. Refer to Wiring Repairs. Did you complete the repair? | -- | Go to Step 14 | --
11 | Repair the open, or high resistance in the ground circuits for the ignition coil. Refer to Wiring Repairs. Did you complete the repair? | -- | Go to Step 14 | --
12 | Replace the ignition coil. Refer to the appropriate procedure:

• | Ignition Coil Replacement - Bank 1

• | Ignition Coil Replacement - Bank 2

Did you complete the replacement?

--

Go to Step 14

--

13 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | --
14 |

1. Clear any DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 2

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 | System OK