Kubota P0262 – Engine Control Module (ECM): Injector Driver #1 Short-To-Power

The ECM detects that the injector driver 'on' voltage is greater than 4.00V for 10 consecutive samples (while battery voltage is under 16.0V). This indicates the injector coil has shorted internally, the injector driver circuit in the engine wiring harness is shorted to a voltage source, or the ECM's internal driver has failed.

• E3 Series
• WG1605-G-E3
• WG1605-L-E3
• WG1605-GL-E3
• WG972
• WG2503
• WG3800
• Toro mowers
• Genie lifts
• PowerBoss sweepers

1. 1

   Visual Inspection: Inspect the wiring harness from the ECM (90-pin connector) to Fuel Injector #1. Look for melted insulation, chafing, or pinched wires that could cause a short to power.

2. 2

   Connector Check: Disconnect the Injector #1 connector and check for water intrusion, bent pins, or corrosion.

3. 3

   Coil Resistance Test: Measure the internal resistance of Fuel Injector #1 across its pins. If the resistance is out of OEM specification (reads as a dead short), the injector coil has failed internally.

4. 4

   Harness Voltage Check: With the key ON and the injector disconnected, probe the ground/control wire on the harness side. If it shows 12V when it shouldn't, the harness is shorted to power.

5. 5

   ECM Verification: If the injector tests good and the wiring harness shows no shorts, the fault lies within the ECM's internal low-side driver.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Isolate the Fault

   Based on your diagnostic checks, determine if the fault is the injector, the harness, or the ECM.

3. 3

   Replace the Injector (if faulty)

   Relieve fuel system pressure. Disconnect the electrical connector from Injector #1. Remove the fuel rail/retaining hardware securing the injector. Pull the faulty injector out, ensuring the old O-rings are removed from the port. Lubricate the O-rings on the new injector with clean engine oil and press it firmly into the fuel rail and intake manifold. Reinstall the retaining hardware and reconnect the electrical plug.

4. 4

   Repair the Harness (if faulty)

   Locate the shorted section of the wire between the injector and the ECM. Cut out the damaged section and solder/heat-shrink a new wire, or replace the affected engine harness entirely.

5. 5

   Replace the ECM (if faulty)

   Disconnect the 90-pin connector, unbolt the ECM, and install the new module. (Note: A new ECM will likely require dealer-level flashing/calibration using the Kubota KGST diagnostic software).

6. 6

   Finalize

   Reconnect the battery, cycle the key to prime the fuel system (check for leaks), and clear the DTCs using an OBD/J1939 scan tool. Run the engine to verify the code does not return.