Buick Regal: DTC P0351-P0354, P2300, P2301, P2303, P2304, P2306, P2307, P2309, or P2310

Diagnostic Instructions

• Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis
• An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions

DTC Descriptor

DTC P0351

Ignition Coil 1 Control Circuit

DTC P0352

Ignition Coil 2 Control Circuit

DTC P0353

Ignition Coil 3 Control Circuit

DTC P0354

Ignition Coil 4 Control Circuit

DTC P2300

Ignition Coil 1 Control Circuit Low Voltage

DTC P2301

Ignition Coil 1 Control Circuit High Voltage

DTC P2303

Ignition Coil 2 Control Circuit Low Voltage

DTC P2304

Ignition Coil 2 Control Circuit High Voltage

DTC P2306

Ignition Coil 3 Control Circuit Low Voltage

DTC P2307

Ignition Coil 3 Control Circuit High Voltage

DTC P2309

Ignition Coil 4 Control Circuit Low Voltage

DTC P2310

Ignition Coil 4 Control Circuit High Voltage

Diagnostic Fault Information

Circuit/System Description

For an overview of the component/system, refer to:Electronic Ignition System Description

The ECM controls the spark event for each cylinder through individual ignition coil control circuits.

When the ECM commands the ignition control circuit On, electrical current flows through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM commands the ignition control circuit Off, interrupting current flow through the primary winding. The collapsing magnetic field created by the primary winding induces a high voltage in the secondary winding, which is connected to the spark plugs.

Conditions for Running the DTC

• Engine=Running
• Ignition Voltage=Greater than 11 V

Frequency the DTC runs=Continuously - After the running conditions are met

Conditions for Setting the DTC

Control Circuit=Commanded state does not match the actual state

Actions Taken When the DTC Sets

DTCs listed in the DTC Descriptor Category=Type A DTC

Conditions for Clearing the DTC

DTCs listed in the DTC Descriptor Category=Type A DTC

Reference Information

Schematic Reference

Engine Controls Wiring Schematics (LTG)

Connector End View Reference

Component Connector End View Index and Inline Harness Connector End View Index

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

Special Tools

J-26792 Ignition Spark Tester

Equivalent regional tools: Special Tools (Diagnostic Tools) and Special Tools (Mechanical Tools)

Circuit/System Verification

1. Engine - Running.

2. Verify the scan tool parameter:

• Ignition Coil 1 - 4 Control Circuit High Voltage Test Status = OK or Not Run
• Ignition Coil 1 - 4 Control Circuit Low Voltage Test Status = OK or Not Run
• Ignition Coil 1 - 4 Control Circuit Open Test Status = OK or Not Run
• If not the specified state

Refer to: Circuit/System Testing

• Go to next step: If the specified state

3. Verify the scan tool parameter:

• Ignition Coil 1 - 4 Control Circuit High Voltage Test Status = OK or Not Run
• Ignition Coil 1 - 4 Control Circuit Low Voltage Test Status = OK or Not Run
• Ignition Coil 1 - 4 Control Circuit Open Test Status = OK or Not Run
• Perform the action while monitoring the parameter:
• Wiggle the harness and connector:T8 Ignition Coil
• Wiggle the harness and connector:K20 Engine Control Module
• If not the specified state

Repair as necessary - Wiring / Terminal(s) / Electrical Connector(s)

• Go to next step: If the specified state

4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Verify the DTC does not set.

• If the DTC sets

Refer to: Circuit/System Testing

• Go to next step: If the DTC is not set

5. All OK.

Circuit/System Testing

NOTE: It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

1. Ignition/Vehicle & All vehicle systems - Off.

2. Disconnect the appropriate electrical connector:T8 Ignition Coil.

3. Test for less than 10 ohms between the test points: Ground circuit terminal 1/A & Ground.

• If 10 ohms or greater

1. Disconnect the ground connection: Ground terminal
2. Test for less than 2 ohms between the test points: Ground circuit terminal 1/A@Component harness & The other end of the circuit @Ground terminal
   • If 2 ohms or greater - Repair the open/high resistance in the circuit.
   • If less than 2 ohms - Repair the open/high resistance in the ground connection.

• Go to next step: If less than 10 ohms

4. Ignition - On / Vehicle - In Service Mode.

5. Verify a test lamp does not turn On between the test points: Control circuit terminal 3/C & B+.

• If the test lamp turns On

1. Ignition/Vehicle - Off & Remove - Test lamp
2. Disconnect the electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Control circuit terminal 3/C@Component harness & Ground
   • If less than infinite resistance - Repair the short to ground on the circuit.
   • If infinite resistance - Replace the component: K20 Engine Control Module

• Go to next step: If the test lamp does not turn On

6. Remove - Test Lamp.

7. Engine - Running.

8. Verify the scan tool parameter: Ignition Coil 1 - 4 Control Circuit High Voltage Test Status = OK or Not Run.

• If not the specified state

1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: K20 Engine Control Module
3. Test for less than 1 V between the test points:Control circuit terminal 3/C@Component harness & Ground
   • If 1 V or greater - Repair the short to voltage on the circuit.
   • If less than 1 V - Replace the component: K20 Engine Control Module

• Go to next step: If the specified state

9. Ignition/Vehicle - Off.

10. Connect a 3 A fused jumper wire between the test points:Control circuit terminal 3/C & Ignition circuit terminal 4/D.

11. Engine - Running.

12. Verify the scan tool parameter: Ignition Coil 1 - 4 Control Circuit High Voltage Test Status = OK or Not Run.

• If not the specified state

1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
2. Disconnect the electrical connector: K20 Engine Control Module
3. Test for less than 2 ohms between the test points: Control circuit terminal 3/C@Component harness & The other end of the circuit@Control module harness
   • If 2 ohms or greater - Repair the open/high resistance in the circuit.
   • If less than 2 ohms - Replace the component: K20 Engine Control Module

• Go to next step: If the specified state

13. Test or replace the component:T8 Ignition Coil.

Component Testing

NOTE: Circuit/System Testing must be performed before proceeding with Component Testing.

1. Ignition/Vehicle - Off.

2. Remove the appropriate component:T8 Ignition Coil - Leave the electrical connector connected.

3. Install the special tool: J-26792 Ignition Spark Tester.

4. Engine - Running.

NOTE: An erratic or weak spark is considered a no spark condition.

5. Verify there is spark at the tool.

• If there is no spark

Replace the component:T8 Ignition Coil

• Go to next step: If there is spark

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification

• Ignition Coil Replacement
• For control module replacement, programming, and setup refer to: Control Module References

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