GM Service Manual Online
For 1990-2009 cars only

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 provide an overview of each diagnostic category.

DTC Descriptors

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

DTC P2312: Ignition Coil 5 Control Circuit Low Voltage

DTC P2313: Ignition Coil 5 Control Circuit High Voltage

DTC P2315: Ignition Coil 6 Control Circuit Low Voltage

DTC P2316: Ignition Coil 6 Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ignition Voltage - Bank 1

P0300-P0306, P2300, P2306, P2312

P0300-P0306

--

P0300, P0301, P0303, P0305

Ignition Voltage - Bank 2

P0300-P0306, P2303, P2309, P2315

P0300-P0306

--

P0300, P0302, P0304, P0306

Ignition Coil 1 Control Circuit

P2300

P0301

P2301

P0300, P0301

Ignition Coil 2 Control Circuit

P2303

P0302

P2304

P0300, P0302

Ignition Coil 3 Control Circuit

P2306

P0303

P2307

P0300, P0303

Ignition Coil 4 Control Circuit

P2309

P0304

P2310

P0300, P0304

Ignition Coil 5 Control Circuit

P2312

P0305

P2313

P0300, P0305

Ignition Coil 6 Control Circuit

P2315

P0306

P2316

P0300, P0306

Circuit/System Description

The ignition system on this engine uses individual ignition coils and ignition control (IC) circuits for each cylinder. Ignition voltage is supplied to each bank of ignition coils. The engine control module (ECM) controls the ignition system operation. The ECM controls each coil using the IC circuits. The ECM commands the IC circuit low when a spark event is requested.

The sequencing and timing are ECM controlled.

Conditions for Running the DTC

    • The engine is operating.
    • The ignition voltage is between 10.5-18 volts.
    • The engine speed is between 600-5,000 RPM.
    • The DTCs run continuously once per crankshaft revolution after the above conditions are met for 20 crankshaft revolutions.

Conditions for Setting the DTC

P2300, P2303, P2306, P2309, P2312, or P2315

The ECM detects the ignition control circuit is shorted to ground for more than 4 seconds or a cumulative of 50 seconds.

P2301, P2304, P2307, P2310, P2313, or P2316

The ECM detects the ignition control circuit is shorted to voltage for more than 4 seconds or a cumulative of 50 seconds.

Action Taken When the DTC Sets

DTCs P2300, P2301, P2303, P2304, P2306, P2307, P2309, P2310, P2312, P2313, P2315, and P2316 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P2300, P2301, P2303, P2304, P2306, P2307, P2309, P2310, P2312, P2313, P2315, and P2316 are Type B DTCs.

Diagnostic Aids

    • Inspect the ignition coils for aftermarket devices. An aftermarket device connected to the ignition coil circuits, may cause this DTC to set.
    • If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Description and Operation

Electronic Ignition (EI) System Description

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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification

  1. Operate the engine for 30 seconds, observe the scan tool DTC information parameter. DTCs P2300, P2301, P2303, P2304, P2306, P2307, P2309, P2310, P2312, P2313, P2315, and P2316 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 at the appropriate ignition coil.
  2. Important: The ignition circuit supplies voltage to other components. Make sure you test all circuits for a short to ground or test all components for being shorted that share the ignition circuit.

  3. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground.
  4. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition voltage circuit and replace as necessary.
  5. Crank or start the engine, test for 200-400 mV between the appropriate IC circuit terminal C and ground.
  6. If less than the specified value, test the IC circuit for a short to ground or an open/high resistance. If the circuit/connection tests normal, replace the ECM.
    If greater than the specified value, test the IC circuit for a short to voltage. If the circuit/connection tests normal, replace the ECM.
  7. Test for 5 ohms or less between the low reference circuit terminal B and the ECM housing.
  8. If greater than the specified value, test for an open/high resistance in the low reference circuit. If the circuit/connection tests normal, replace the ECM.
  9. Test for 5 ohms or less between the ground circuit terminal A and ground.
  10. If greater than the specified value, repair the open, or high resistance in the ground circuit.
  11. If all circuits/connections test normal, replace the ignition coil.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Ignition Coil Replacement - Bank 1
    •  Ignition Coil Replacement - Bank 2
    •  Control Module References for engine control module replacement, setup, and programming