For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P2301: Ignition Coil 1 Control Circuit
DTC P2304: Ignition Coil 2 Control Circuit
DTC P2307: Ignition Coil 3 Control Circuit
DTC P2310: Ignition Coil 4 Control Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Ignition Coil 1 Control Circuit | -- | -- | -- | P2301 | --
Ignition Coil 2 Control Circuit | -- | -- | -- | P2304 | --
Ignition Coil 3 Control Circuit | -- | -- | -- | P2307 | --
Ignition Coil 4 Control Circuit | -- | -- | -- | P2310 | --

### Circuit/System Description

The ignition system consists of one integrated and sealed ignition coil/module assembly for the 4 cylinders. The engine control module (ECM) controls the individual coils by transmitting timing pulses on the ignition control (IC) circuit of each ignition coil to enable a spark event. When the engine is running the ECM monitors each IC circuit for improper voltage levels. The ignition coil/module assembly has the following circuits:

• | Ignition voltage

• | Ground

• | IC for each coil

### Conditions for Running the DTCs

• | DTC P0340, P0341, P0365, or P0366 is not set.

• | The engine coolant temperature (ECT) is warmer than -30°C (-22°F).

• | The engine is running.

• | The ignition 1 voltage signal is greater than 10 volts.

• | These DTCs run continuously within the enabling conditions.

### Conditions for Setting the DTCs

The ECM detects a short to voltage on an IC circuit for greater than 2 seconds.

### Action Taken When the DTC Sets

DTCs P2301, P2304, P2307, P2310 are Type B DTCs.

### Conditions for Clearing the MIL/DTC

DTCs P2301, P2304, P2307, P2310 are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### 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 for scan tool information

### Circuit/System Verification

• | Start and idle the engine.

• | 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.

### Circuit/System Testing

1. Determine the cylinder that is misfiring.
2. Ignition OFF, disconnect the harness connector at the ignition coil/module assembly.
3. Ignition ON, verify that a test lamp does not illuminate between ground and the affected IC circuit terminal listed below:

• | IC 1 circuit: terminal 6

• | IC 2 circuit: terminal 5

• | IC 3 circuit: terminal 4

• | IC 4 circuit: terminal 3

⇒ | If the test lamp illuminates, test the IC circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. If the circuits test normal, replace the ignition coil/module assembly.

### Repair Instructions

• | Ignition Coil Replacement

• | Control Module References for ECM replacement, setup, and programming

### Repair Verification

If the customer concern was a flashing MIL, perform the following procedure:

1. Install any components that have been removed or replaced during diagnosis.
2. Perform any adjustments, programming, or setup procedures that are required when a component is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 60 seconds.
5. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
6. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420. Refer to DTC P0420.