Case IH 3118 – Engine Control Unit (ECU A-095): Internal 12V supply voltage is too high

The Electronic Control Unit (ECU) monitors its internal 12V supply voltage. If the ECU determines that this voltage value is higher than the expected upper limit, this fault code is triggered.

• Steiger T4B
• Magnum Tractors (MX210, MX230, MX255, MX285, 310, Series 4 (235-340))
• Axial-Flow Combines 240 Series (7230, 8230, 9230)
• Steiger Tractors
• Puma & Maxxum Tractors (Maxxum 140)
• Sugar Cane Harvesters (A8000, A8800)

1. 1

   Verify Active Status: Use the Electronic Service Tool (EST) to check if the fault code is currently active or if it was an intermittent historical code.

2. 2

   External Power Supply Check: Ensure that the tractor's battery power supply has not been connected to an external power supply (like a jump box or high-voltage charger). If an external power supply is connected, disconnect it and test the system for normal operation.

3. 3

   Battery Voltage Check: Check the battery voltage on the instrument cluster while starting the engine and running it at 2000 RPM to ensure the alternator is not overcharging the system.

4. 4

   Harness & Connector Inspection: Visually inspect the relevant harnesses and ECU connectors for damage, bent or dislocated pins, corroded terminals, or broken wires. Verify that the connectors are fully seated.

5. 5

   Flex Test: Flex the involved wiring harnesses while operating the machine and monitoring the display to reveal any intermittent breaks or shorts to a high-voltage source.

1. 1

   Resolve External Voltage Issues

   If the machine was connected to an external power supply or if the alternator is overcharging, resolve the charging system issue first, clear the code, and return the machine to service.

2. 2

   Repair Wiring

   If you find damage during the harness inspection or if the display indicates abnormal readings during the flex test, repair the damaged wiring or connectors. Erase the fault code and verify the error has been resolved.

3. 3

   Software Re-flash

   If the wiring and external voltage are normal, check the ECU A-095 for the appropriate software version. Re-flash the ECU using the EST if necessary. If the fault is resolved after the re-flash, return the machine to service.

4. 4

   Replace the ECU

   If the ECU A-095 cannot be re-flashed, or if re-flashing does not resolve the internal voltage fault, the ECU A-095 has suffered an internal hardware failure and must be replaced.