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 coils consist of the following circuits:

The ECM detects an open, short to ground, or short to voltage on the IC circuit.

DTC P0351, P0352, P0353, and P0354 are Type B DTCs.

The mounting bracket for the coil assembly provides the ground for the ignition coils. Ensure the mounting bolts are torqued to the correct specification. Refer to Fastener Tightening Specifications .

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. DTCs 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 5 ohms between the ground circuit terminal B and ground.

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

3. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal A 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 and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary.

Important: Set the DMM to the AC Hertz scale for this test.

4. Connect a DMM between the appropriate ignition control circuit listed below and ground.

•	Ignition coil 1 control terminal D

•	Ignition coil 2 control terminal G

•	Ignition coil 3 control terminal F

•	Ignition coil 4 control terminal E

5. Engine cranking, test for more than 2 hertz between the appropriate ignition control circuit and ground.

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

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.