Case IH 3065 – Engine ECU: Cylinder 5 - Injector Cable Short circuit (Low Side to Battery)

The Engine Control Module (ECM) has detected that the low-side control circuit for the fuel injector on cylinder 5 is shorted to a voltage source (battery positive/B+), preventing the ECM from properly controlling the injector.

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• Case IH Axial-Flow 6130
• Case IH Axial-Flow 6140
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• Case IH Axial-Flow 9230
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• Case IH Patriot 3530
• Case IH Patriot 4030
• Case IH Patriot 4430
• Case IH Patriot 4440
• Case IH Titan 3030
• Case IH Titan 3530
• Case IH Titan 4030
• Case IH Titan 4430
• Case IH Titan 4440

1. 1

   Turn the keyswitch to the OFF position to remove electrical power from the engine ECM and prevent electrical shock

2. 2

   Inspect the injector wiring harness (especially under the valve cover) for aging, brittle insulation, or cracking that could cause a short

3. 3

   Disconnect the injector harness from the ECU, turn the key ON, and test for voltage from the cylinder 5 pin to chassis ground (should be no voltage)

4. 4

   Perform a continuity test between the harness end connectors to check for a short circuit across the pins

5. 5

   If the wiring harness tests good, check the internal solenoid of the cylinder 5 fuel injector for an internal short

1. 1

   Disconnect power

   Turn off the machine and disconnect battery power to the ECM.

2. 2

   Access wiring harness

   Remove the engine valve cover to access the internal fuel injector wiring harness.

3. 3

   Disconnect injector

   Disconnect the harness from the Cylinder 5 fuel injector.

4. 4

   Repair or replace harness

   If the diagnostic tests proved the harness is shorted, trace the wiring back to the ECM connector. Repair the damaged wire insulation or replace the entire injector wiring harness.

5. 5

   Extract fuel injector

   If the harness is intact but the injector solenoid is shorted, remove the high-pressure fuel lines and extract the Cylinder 5 fuel injector.

6. 6

   Install new injector

   Install the new fuel injector using new O-rings and gaskets.

7. 7

   Reassemble components

   Reinstall the injector wiring harness and valve cover.

8. 8

   Clear fault codes

   Reconnect the ECM, turn the key on, and clear the fault codes using a diagnostic tool.