GM Service Manual Online
For 1990-2009 cars only

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 ignition control circuit
    • The ignition 1 voltage circuit
    • Two ground circuits

The sequencing and timing are ECM controlled. If the ECM detects the IC circuit is shorted to voltage, this DTC sets.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P2301 Ignition Coil 1 Control Circuit High Voltage
    • DTC P2304 Ignition Coil 2 Control Circuit High Voltage
    • DTC P2307 Ignition Coil 3 Control Circuit High Voltage
    • DTC P2310 Ignition Coil 4 Control Circuit High Voltage
    • DTC P2313 Ignition Coil 5 Control Circuit High Voltage
    • DTC P2316 Ignition Coil 6 Control Circuit High Voltage

Conditions for Running the DTC

    • The engine is operating.
    • The engine speed is between 600-5,000 RPM.
    • The ignition voltage is between 10.5-18 volts.
    • This DTC runs continuously once the above conditions are met.

Conditions for Setting the DTC

    • The ECM detects the IC circuit is shorted to voltage.
    • The above condition is present for less 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 Engine Controls 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 number below refers to the step number on the diagnostic table.

  1. This step tests that the ECM is commanding the ignition coil ON and OFF via the ignition control circuit. If the frequency is not between 3-20 Hz, test the ignition control circuit for a short to voltage.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Important: A short to voltage on an ignition control (IC) circuit damages the ignition coil. Do NOT replace the ignition coil until this diagnostic procedure instructs you to replace the ignition coil.

  1. Start the engine.
  2. Observe the DTC Info with a scan tool.

Does DTC P2301, P2304, P2307, P2310, P2313, or P2316 fail this ignition?

--

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

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 10

7

Probe both of the ground circuits of the ignition coil with a test lamp connected to B+. Refer to Troubleshooting with a Test Lamp .

Does the test lamp illuminate at both circuits?

--

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 engine control module (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 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:

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 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 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