Case IH 17655 (F-518403-04) - ECU – Engine Control Module (ECM / ECU) / Bosch MD1CE101: ECU 12/24 volt actuator supply 9 is shorted to battery voltage

The engine control module is detecting unexpected battery voltage on the circuit that supplies power to a specific set of actuators (Supply 9, pins 1.05 and 1.08 on the MD1CE101 control unit), likely due to a wiring short or an internal failure in an actuator.

• VESTRUM CVX
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1. 1

   Pinpoint the Circuit: Locate pins 1.05 and 1.08 on the Bosch MD1CE101 ECU harness connector.

2. 2

   Harness Inspection: Disconnect the battery and inspect the wiring harness leading from pins 1.05 and 1.08 to the engine actuators. Look for chafing, melted insulation, or pinched wires where the harness might be rubbing against a 12V/24V power source.

3. 3

   Actuator Isolation: Disconnect the actuators powered by Supply 9 one by one. Re-check the circuit voltage/continuity. If the short to battery voltage disappears when a specific actuator is unplugged, that actuator has an internal short.

4. 4

   Continuity Testing: With the ECU and actuators unplugged, use a multimeter to test the Supply 9 harness wires for continuity to battery positive. If continuity exists, the harness is shorted.

1. 1

   Repair the Harness

   If the diagnostic tests reveal a short to battery voltage in the wiring harness, repair the damaged section of the wire or replace the affected harness section. Ensure the new wiring is properly loomed and routed away from heat sources and sharp edges.

2. 2

   Replace the Faulty Actuator

   If isolating the actuators revealed that one is internally shorted to power, replace the faulty actuator.

3. 3

   ECU Replacement (Last Resort)

   If the wiring harness tests perfectly fine and all actuators are functioning without internal shorts, the short to battery voltage may be internal to the Bosch MD1CE101 ECU itself. In this case, the ECU must be replaced and reprogrammed by a dealer.

4. 4

   Clear Codes

   Reconnect all components and batteries. Use a diagnostic scan tool to clear the 17655 (F-518403-04) fault code and run the machine to verify the repair.