Kubota P2310 – Engine Control Module (ECM) / EControls ECM: Spark Coil #4 Primary Short-to-Power

The engine computer has detected an abnormally high voltage condition in the primary control circuit for Ignition Coil #4 (Coil "D"). This is typically caused by a short to power in the engine wiring harness or a short internal to the primary winding of the ignition coil itself.

• WG1605
• WG1605-G-E3
• WG1605-L-E3
• WG1605-GLN-E3
• WG2503
• WG3800
• Toro grounds equipment
• PowerBoss sweepers
• forklifts

1. 1

   Verify battery voltage is stable and between 10.0V and 16.0V, as voltage spikes outside this range can skew ECM dwell calculations.

2. 2

   Inspect the wiring harness leading to Ignition Coil #4 for chafed wires, melted insulation, or areas where the wire might be shorting to a 12V power source. Check the connector for corrosion, water intrusion, or bent pins.

3. 3

   Disconnect Coil #4 and measure the primary resistance with a multimeter. Compare this reading to a known-good coil on the engine (e.g., Coil #1 or #2) to check for an internal short.

4. 4

   Swap Ignition Coil #4 with the coil from another cylinder (e.g., Cylinder #3). Clear the codes and run the engine. If the fault code moves to the new cylinder, the ignition coil is the culprit. If it remains P2310, the issue is in the wiring harness or ECM driver.

5. 5

   With the key ON (engine off), backprobe the Coil #4 connector. If the primary resting voltage remains excessively high when the ECM commands the driver to ground, the ECM driver may be internally shorted.

1. 1

   Disconnect Power

   Disconnect the negative battery cable before performing electrical repairs to prevent further ECM damage.

2. 2

   Address Wiring Issues

   If the harness inspection revealed a short to power, cut out the damaged section of the wire and solder/heat-shrink a new section of automotive-grade wire. Ensure the harness is routed away from extreme heat sources or sharp brackets.

3. 3

   Replace the Ignition Coil

   If the coil swap test proved the coil was internally shorted, remove the mounting bolt for Coil #4, pull the coil off the spark plug, and install the new OEM replacement coil.

4. 4

   Inspect the Spark Plug

   Inspect and replace the spark plug on Cylinder #4 while the coil is removed, as a fouled or excessively worn spark plug can cause increased resistance and premature coil failure.

5. 5

   Reassemble and Clear Codes

   Reconnect the coil harness and the battery. Use an OBD-II / J1939 diagnostic scanner to clear the P2310 fault code.

6. 6

   Test Drive

   Run the engine to operating temperature and verify that the misfire is gone, the MIL remains off, and the engine revs past the previous low-rev limit.