Case IH 17689 (F-518405-04) - ECU – Bosch MD1CE101: ECM 12/24 volt actuator supply 7 is shorted to ground

The Engine Control Module has detected a short circuit to the chassis ground on the actuator supply circuit number 7 (MD1CE101 pins 1.06 and 1.09), which provides high-side power to the Hose Heater Relay and the SCR Heating Valve.

• VESTRUM CVX
• Magnum (CVT/CVX 265 through 400)
• Maxxum (CVX 115 through 180)
• Optum (CVX 250, 270, 300, 340)
• Puma (X 140, X 150, CVX 150-260)
• Steiger (385 through 555)
• Steiger Quadtrac (475 through 715)
• Vestrum
• Axial-Flow (5150, 6150, 7150, 7160, 7240, 7250, 8240, 8250, 8260, 9250)
• Patriot 3250
• Patriot 4450
• Farmlift 737
• Farmlift 742
• Graders (836C)
• Wheel Loaders (621G, 721G, 821G, 1021G)
• Excavators (CX130E, CX210E, CX300E)

1. 1

   Locate Connector 2 (Code F, a 48-pin Bosch connector) on the MD1CE101 ECM.

2. 2

   Inspect the wiring harness leading from ECM pins 1.06 and 1.09 for chafing, melted insulation, or pinch points against the chassis or hot engine components that could cause a short to ground.

3. 3

   Disconnect the DEF Hose Heater Relay and the SCR Heating Valve. Use a multimeter to test the resistance of these components to ground to see if they have failed internally.

4. 4

   With the actuators unplugged, check the harness side of pins 1.06 and 1.09 for continuity to ground. If continuity exists, the harness is shorted. If it does not, one of the actuators is internally shorted.

1. 1

   Disconnect power

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

2. 2

   Disconnect ECM

   Disconnect the 48-pin Bosch connector (Connector 2 / Code F) from the MD1CE101 ECM.

3. 3

   Probe for short

   Using a digital multimeter, probe pins 1.06 and 1.09 on the harness side for a short to ground.

4. 4

   Repair wiring harness

   If the harness is shorted, physically trace the wiring from the ECM to the Hose Heater Relay and SCR Heating Valve. Repair the damaged section of the wire using OEM-approved splicing methods and heat shrink, or replace the affected harness section.

5. 5

   Replace faulty actuator

   If the harness tests good, test the Hose Heater Relay and SCR Heating Valve individually. Replace whichever component is internally shorted to ground.

6. 6

   Reconnect components

   Reconnect all components and the ECM connector.

7. 7

   Clear fault code

   Reconnect the battery, turn on the ignition, and use a diagnostic service tool to clear the 17689 (F-518405-04) fault code.

8. 8

   Verify repair

   Run the engine and verify that the DEF heating system operates normally without the code returning.