GM Service Manual Online
For 1990-2009 cars only

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 control
    • The IC 2 control
    • The IC 3 control

If the ECM detects an incorrect signal in the IC circuits, 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

Conditions for Running the DTC

    • The engine is operating.
    • DTCs P0351, P0352, and P0353 run continuously once the above condition is met.

Conditions for Setting the DTC

The ECM detects an incorrect signal 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.
    • 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.

  1. This step tests for an open or short to ground in the ignition 1 voltage circuit of the ignition coil circuit.

  2. 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

Go to Diagnostic System Check - Engine Controls

2

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

Did DTC P0351, P0352, OR P0353 fail this ignition?

--

Go to Step 4

Go to Step 3

3

  1. Turn OFF the ignition for 30 seconds.
  2. Start the engine.
  3. Operate the vehicle within the Conditions for Running the DTC.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Intermittent Conditions

4

  1. Turn OFF the engine.
  2. Disconnect the ignition coil harness connector.
  3. Probe the ignition 1 voltage circuit of the ignition coil with a test lamp connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 9

5

  1. Connect a DMM between the appropriate ignition control circuit and a good ground.
  2. Set the DMM to the AC Hertz scale. Refer to Measuring Frequency in Wiring Systems.
  3. Observe the DMM while cranking the engine.

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:

    • An open
    • A short to ground
    • A short to voltage
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

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 in Wiring Systems.

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 in Wiring Systems.

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 in Wiring Systems.

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

  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.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 13

13

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK