This diagnostic monitors the primary circuitry of individual ignition coils for the successful completion of an ignition event. The ignition trigger signal and ignition fail-safe input signal provide crucial information in the control of ignition system timing and the activation of the fail-safe function. Based on the initial timing angle, calculated from the crankshaft and the camshaft position signals, the powertrain control module (PCM) calculates the ignition trigger signal. The ignition trigger signal is then sent to the ignition control circuitry located in each ignition coil. The ignition control circuitry initiates the ignition dwell period by commanding the power transistor ON. When the PCM determines the proper time to provide spark, the PCM turns OFF the ignition trigger signal. In response to the PCM signal, the ignition coil control circuitry turns OFF the power transistor, producing a high voltage discharge from the secondary coil windings. After the spark has occurred, the control circuitry sends an ignition fail-safe input signal back to the PCM, confirming that an ignition event has taken place. If the ignition fail-safe input signal is not received by the PCM, a cylinder specific DTC will set. The ignition coils consist of the following circuits:

No ignition coil fail-safe input signal is received by the PCM for 2 consecutive ignition trigger signal cycles.

DTCs P0351, P0352, P0353, and P0354 are Type A DTCs.

Inspect for the following conditions:

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Ignition (EI) System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Engine running, observe the DTC information with a scan tool. DTC P0351, P0352, P0353, and P0354 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the ignition coil.
2. Ignition OFF, test for less than 10  ohms of resistance between the coil ground circuit terminal 4 and ground G104.

⇒	If greater than the specified range, test the coil ground circuit for an open/high resistance.

3. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, test the IG2 ignition relay. Refer to Ignition Relay Diagnosis.

Important: Ensure that DTCs are cleared before performing this test.

4. Engine cranking, test for 0.2-1.0 volts between the ignition coil control circuit terminal 3 and ground.

⇒	If less than the specified range, test the control circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the PCM.

5. Test for 4.8-5.2 volts between the ignition fail-safe circuit terminal 2 and ground.

⇒	If less than the specified range, test the fail-safe circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.

⇒	If greater than the specified range, test the fail-safe circuit for a short to voltage. If the circuit tests normal, replace the PCM.

6. If all circuits test normal, test or replace the ignition coil.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.