Case IH 3281 – Engine Control Unit (ECU) A-095: 12V sensor supply 1 voltage is too low

The control module has monitored its 12-volt sensor supply circuits and determined that the voltage on sensor supply 1 has dropped below the acceptable operating threshold.

• Steiger T4B
• 240 Series Axial-Flow® Combines (7240, 8240, 9240)
• Puma Series Tractors
• Farmall 40-45-50 Tractors (with Cab and CVT Transmission)
• A8000 / A8800 Series Sugarcane Harvesters

1. 1

   Verify that the tractor/machine battery power supply has not been connected to an external power supply (like a jump starter or external charger). If an external power supply is connected, disconnect it and test the system for normal operation.

2. 2

   Verify that the fault code is still present and in an active state on the monitor.

3. 3

   Visually inspect the wiring harnesses and connectors (specifically connector X-917 at the ECU) to identify damaged, bent, or dislocated pins, corroded terminals, or broken wires.

4. 4

   Verify that the connectors are completely seated. Flex the involved harnesses while observing the monitor to reveal any intermittent breaks or shorts in the wiring.

1. 1

   Disconnect External Power

   If an external power supply was found connected during the diagnostic checks, remove it and cycle the key to see if the code clears.

2. 2

   Inspect Connector X-917

   Locate ECU A-095 and disconnect connector X-917. Inspect pin 84 (the 12V sensor supply 1 pin) for corrosion or damage.

3. 3

   Test for Shorts to Ground

   Using a multimeter, check for continuity from the engine harness side of the sensor supply circuits to chassis ground.

4. 4

   Repair Wiring

   If there is continuity to ground where there shouldn't be, there is a short-to-ground condition in the engine harness. Locate the chafed or damaged wire in the harness and repair it.

5. 5

   Software Re-flash

   If the wiring and sensors are intact and no shorts are found, check the ECU A-095 for the appropriate software. Re-flash the ECU software if necessary.

6. 6

   Replace ECU

   If the fault has not been resolved after repairing wiring and verifying/re-flashing the software, the ECU A-095 has suffered an internal failure and must be replaced.