GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The ignition system on this engine uses an individual ignition coil for each cylinder. The engine control module (ECM) controls the spark event for each cylinder through 8 individual ignition control (IC) circuits. When the ECM commands the IC circuit ON, electrical current will flow through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM will command the IC circuit OFF, interrupting current flow through the primary winding. The magnetic field created by the primary winding will collapse across the secondary coil winding, producing a high voltage across the spark plug electrodes. The ECM uses information from the crankshaft position (CKP) and the camshaft position (CMP) sensor for sequencing and timing of the spark events. Each ignition coil/module has the following circuits:

    • An ignition 1 voltage circuit
    • A ground circuit
    • An IC circuit
    • A low reference circuit

If the ECM detects that the IC circuit has an incorrect voltage level, DTC P0351-P0358 will set.

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
    • DTC P0357 Ignition Coil 7 Control Circuit
    • DTC P0358 Ignition Coil 8 Control Circuit

Conditions for Running the DTC

    • The engine is running.
    • DTC P0351-P0358 runs continuously when the above condition is met.

Conditions for Setting the DTC

The ECM detects the IC circuit is grounded, open, or shorted to voltage for less than 1 second.

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.

Test Description

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

  1. This step verifies the integrity of the IC circuit and the ECM output.

  2. This step tests for a short to voltage on the IC circuit.

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 - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  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 you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

  1. Turn OFF the engine.
  2. Disconnect the respective ignition coil electrical connector.
  3. Disconnect the respective fuel injector electrical connector.
  4. Start the engine.
  5. Measure the frequency at the ignition (IC) circuit with the DMM set to DC Hertz. Refer to Measuring Frequency .

Is the frequency within the specified range?

3-20 Hz

Go to Step 7

Go to Step 4

4

  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage from the IC circuit of the ignition coil to a good ground with a DMM.

Is the voltage more than the specified value?

1 V

Go to Step 13

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the engine control module (ECM) connector.
  3. Test the IC circuit between the ignition coil connector and the ECM connector for continuity with the DMM.

Does the DMM indicate continuity?

--

Go to Step 6

Go to Step 14

6

Test the respective IC circuit for a short to ground. Refer to Testing for Short to Ground .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 10

7

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit of the ignition coil with a test lamp that is connected to battery ground. Refer to Troubleshooting with a Test Lamp .

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 11

8

Probe the ground circuit of the ignition coil with a test lamp connected to battery voltage. Refer to Troubleshooting with a Test Lamp .

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 12

9

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 17

Go to Step 15

10

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 17

Go to Step 16

11

Repair the open or high resistance in the ignition 1 voltage circuit. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 17

--

12

Repair the open or high resistance in the ground circuit for the ignition coil. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 17

--

13

Repair the IC circuit for a short to voltage. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 17

--

14

Repair the open or high resistance in the IC circuit. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 17

--

15

Replace the ignition coil. Refer to Ignition Coil Replacement .

Did you complete the replacement?

--

Go to Step 17

--

16

Replace the ECM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 17

--

17

  1. Clear the 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 18

18

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