FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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P0351




DTC P0351 or P0352

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Strategy Based Diagnosis Strategy Based Diagnosis
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions

DTC Descriptors
DTC P0351
- Ignition Coil 1 and 4 Control Circuit

DTC P0352
- Ignition Coil 2 and 3 Control Circuit

Diagnostic Fault Information






Circuit/System 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 coils consist of the following circuits:

* The ignition 1 voltage
* The IC 1 and 4 control
* The IC 2 and 3 control

Conditions for Running the DTC

* The engine is operating.
* The DTCs run continuously once the above condition is met.

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

* DTC P0351 and P0352 are Type B DTCs.
* The ECM commands open loop fuel control.

Conditions for Clearing the DTC

DTC P0351 and P0352 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (w/Throttle Actuator Controls) Electrical DiagramsEngine Controls Schematics (w/o Throttle Actuator Control) Electrical Diagrams

Connector End View Reference
* Engine Controls Connector End Views (w/ Throttle Actuator Control) Engine Controls Connector End Views (w/ Throttle Actuator Control)Engine Controls Connector End Views (w/o Throttle Actuator Control) Engine Controls Connector End Views (w/o Throttle Actuator Control)
* Engine Control Module Connector End Views (w/ Throttle Actuator Control) Engine Control Module Connector End Views (w/ Throttle Actuator Control)Engine Control Module Connector End Views (w/o Throttle Actuator Control) Engine Control Module Connector End Views (w/o Throttle Actuator Control)

Description and Operation

Electronic Ignition (EI) System Description Electronic Ignition (EI) System Description

Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference
* Scan Tool Data List (w/ Throttle Actuator Control) Scan Tool Data List (w/ Throttle Actuator Control)Scan Tool Data List (w/o Throttle Actuator Control) Scan Tool Data List (w/o Throttle Actuator Control)
* Scan Tool Data Definitions (w/ Throttle Actuator Control) Scan Tool Data Definitions (w/ Throttle Actuator Control)Scan Tool Data Definitions (w/o Throttle Actuator Control) Scan Tool Data Definitions (w/o Throttle Actuator Control)
* Scan Tool Output Controls (w/ Throttle Actuator Control) Scan Tool Output Controls (w/ Throttle Actuator Control)Scan Tool Output Controls (w/o Throttle Actuator Control) Scan Tool Output Controls (w/o Throttle Actuator Control)

Circuit/System Verification

1. Engine idling, observe the DTC information with a scan tool. DTC P0351 and P0352 should not set.
2. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the ignition coil.
2. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit 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.


3. Connect a DMM between the appropriate ignition control circuit and ground.
4. While cranking the engine, test for more than 2 hertz between the appropriate ignition control circuit and ground.

If less than 2 hertz, test the ignition control circuit for a short to voltage, short to ground or an open/high resistance. If the circuit/connection test normal, replace the ECM.

5. If all circuits/connections test normal, replace the ignition coil.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Ignition Coil Replacement Service and Repair
* Control Module References Control Module References for engine control module replacement, setup, and programming