Case IH 3883 (F-3507-06) - ECU – Engine Control Unit (ECU) / Bosch MD1CE101: ECU 12/24 volt actuator supply 3 is shorted to ground

The internal power supply circuit within the engine control module that provides voltage to a specific bank of actuators has detected a direct path to ground, pulling the voltage down and preventing the actuators from functioning. The specific circuit is routed through the ECU connector at pins 5.06, 5.09, and 6.25.

• VESTRUM CVX
• Magnum CVT/CVX
• Maxxum CVX
• Optum CVX
• Puma CVX
• Puma X
• Axial-Flow (AF) series
• Farmlift
• Graders
• Case Construction Wheel Loaders

1. 1

   Trace the engine wiring harness starting from the Bosch MD1CE101 ECU connector, specifically focusing on the wires originating from pins 5.06, 5.09, and 6.25. Look for chafed insulation, pinched wires, or areas where the harness may be rubbing against the engine block or chassis, causing a short to ground.

2. 2

   Disconnect the actuators powered by supply 3 one at a time. Use a multimeter to check if the short to ground in the harness clears when a specific actuator is unplugged. If it clears, the actuator itself is internally shorted.

3. 3

   Disconnect the harness from the ECU. Test the harness side of pins 5.06, 5.09, and 6.25 for continuity to ground. If the harness tests good (no short), the short to ground is likely an internal hardware failure within the Bosch MD1CE101 ECU itself.

1. 1

   Disconnect power

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

2. 2

   Resolve external shorts

   If the diagnostic checks revealed a damaged wiring harness, repair the chafed wires using proper soldering and heat-shrink techniques, or replace the affected harness section. If an actuator was found to be internally shorted, replace the faulty actuator.

3. 3

   Replace the ECU

   If the ECU is internally shorted, locate the Bosch MD1CE101 ECU on the engine block. Carefully release the locking levers on the ECU harness connectors and unplug them. Remove the mounting bolts securing the ECU to its bracket and remove the faulty unit. Install the replacement ECU and tighten the mounting bolts. Reconnect the harness connectors, ensuring the locking levers are fully seated.

4. 4

   Program the new ECU

   A replacement Bosch MD1CE101 ECU must be flashed/programmed with the correct firmware and engine calibration files specific to your exact Case IH model and emissions equipment (e.g., SCR/AdBlue systems) using the OEM diagnostic tool.

5. 5

   Finalize repair

   Reconnect the negative battery terminal, turn the key on, and clear the inactive fault codes. Start the engine and verify that code 3883 (F-3507-06) does not return.