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For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2006 🢒 Vibe - FWD 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Electronic Ignition (EI) System Diagnosis

Circuit Description

Each engine cylinder has a dedicated ignition coil assembly. The ignition coil assembly contains the ignition module circuitry. The power distribution circuit supplies system voltage to each coil assembly when the ignition switch is in the ON or START positions. Each coil assembly regulates current flow through the primary coil windings, creating a magnetic field. The powertrain control module (PCM) signals each coil assembly to supply a spark in a cylinder through a trigger circuit. Each assembly does so by opening the primary circuit coil, inducing a high voltage in the secondary circuit coil. The high voltage in the secondary circuit grounds by arcing at the spark plug. This event creates a pulse on the fail safe circuit that the PCM recognizes as a confirmation of spark.

Diagnostic Aids

Check for any of the following conditions:

    • Any circuit malfunction between the ignition coil assembly and the PCM should set a fail safe circuit DTC P0351, P0352, P0353, or P0354.
    • Check the crankshaft position (CKP) sensor engine reference signal with a scan tool. Observe the Engine Speed parameter while cranking the engine. The scan tool should indicate a steady 200-300 RPM while cranking. If erratic values, such as sudden spikes in the engine speed, are displayed, the engine reference signal is not stable enough for dependable ignition system operation.
    • An ignition system that tests OK after sitting may be susceptible to moisture. Spray water on the ignition system components and wiring in order to check for an intermittent failure.

Test Description

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

  1. If there is a fault in either the crankshaft position (CKP) sensor or camshaft position (CMP) sensor circuits, the ignition system can malfunction. Repair the cause of a DTC P0335 or DTC P0340 first.

    2.

  2. If there is a fault in the electrical circuits between the PCM and the ignition coil assemblies, a DTC P0351-P0354 will set. Use the DTC P0351-P0354 diagnostic table in order to repair the ignition system failure.

    3.

  3. This step checks for a condition that can cause a loss of spark, even though the test in step 4 indicated that there was good spark.

    4.

  4. This step checks whether the engine will start and run. A repair that has been performed leading to this step may only have been a contributing cause of a no start condition. Returning to the Engine Cranks but Does Not Run diagnostic table will locate additional causes of the no start condition.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain 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 in Vehicle DTC Information

2

Check for DTCs with a scan tool.

Is a DTC P0335 or P0340 set?

Go to DTC P0335 and DTC P0340

Go to Step 3

3

Is DTC P0351, P0352, P0353, or P0354 set?

Go to DTC P0351-P0354

Go to Step 4

4
  1. Disconnect the electrical connector of each fuel injector.
  2. Disconnect the electrical connector at an ignition coil assembly.
  3. Remove the ignition coil assembly. Refer to Ignition Coil Replacement . Do not remove the spark plugs.
  4. Connect a J 26792 Spark Tester or an equivalent to the spark plug boot of the ignition coil assembly.
  5. Clip the spark tester to ground.
  6. Connect the coil assembly electrical connector.
  7. Crank the engine and observe the spark tester.
  8. Repeat this test for each ignition coil assembly.

Is a crisp blue spark available at all ignition coil assemblies?

Go to Step 7

Go to Step 5

5

Is a crisp blue spark available at one or more ignition coil assemblies?

Go to Step 6

Go to Step 9

6
  1. Turn OFF the ignition.
  2. Replace the suspected faulty ignition coil with a known good ignition coil.
  3. Repeat the test for spark with the J 26792 described in step 4.

Was a crisp blue spark present while cranking the engine?

Go to Step 8

Go to Step 9

7

Inspect the ignition coil assembly boot and terminals for the following conditions:

    • Cracks
    • Corrosion
    • Carbon tracking

Did you find any of the listed conditions?

Go to Step 8

Go to Step 10

8

Replace the faulty ignition coil assembly or assemblies. Refer to Ignition Coil Replacement .

Did you complete the replacement?

Go to Step 10

--

9

Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10

  1. Assemble the ignition system.
  2. Start the engine.

Does the engine start and run?

Go to Step 11

Go to Engine Cranks But Does Not Run

11

Check for DTCs.

Are any DTCs set?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK