Case IH 3811 – Engine Control Unit (ECU): Engine Regulated 5 Volt Sensor Supply # 1 - Too High

The 5-volt reference circuit #1, which supplies power to various engine sensors, is reading a voltage that is above the maximum allowed range (often due to a short to battery voltage or an internal failure within the controller).

• Farmall
• Steiger T4B
• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Farmall series
• Steiger tractors
• Magnum tractors
• Patriot Sprayers

1. 1

   Inspect the 'A' 60-pin connector on the Engine ECU (pins A07 through A13) for corrosion, pushed-out pins, or moisture.

2. 2

   Test the 5-volt sensor supply 1 wiring harness for a short to 12V/battery voltage.

3. 3

   Disconnect the sensors powered by the 5-volt supply #1 one at a time to see if a shorted sensor is pulling the voltage out of range.

1. 1

   Disconnect battery

   Disconnect the battery to ensure safety before removing the module.

2. 2

   Disconnect harness

   Disconnect the 60-pin engine harness connectors from the Engine Controller.

3. 3

   Remove controller

   Remove the mounting hardware and extract the faulty Engine Controller.

4. 4

   Install new controller

   Install the new Engine Controller and reconnect the 60-pin harnesses.

5. 5

   Restore parameters

   Use the appropriate electronic service tool (such as the CNH EST) to 'Restore Self Learning Parameters'.