Case IH 19601 – Engine Control Unit (ECU / ECM): ECU power stage hardware reports a short circuit to battery error

The internal driver circuit (the "power stage") within the Engine Control Unit (ECU) has detected that one of its output pins is shorted to battery voltage (SCB). The ECU expects to see a load or ground on this circuit, but instead, it is receiving 12V/24V directly. This can be caused by a chafed wiring harness touching a power source, an internally shorted actuator/sensor, or a burned-out driver inside the ECU itself.

• Tier 4b
• Puma
• Magnum
• Optum
• Steiger
• Quadtrac
• N-Series Backhoe Loaders
• Wheel Loaders (521F-921F)
• Crawler Dozers

1. 1

   Check for accompanying component-specific codes (e.g., fuel metering unit, pre-supply pump, glow plug relay, or DEF line heater) to identify the specific circuit that is shorting

2. 2

   Disconnect the suspected actuator and the ECU, then use a multimeter to test the specific circuit's wire for continuity to battery positive

3. 3

   Inspect the wiring harness for chafed wires, melted insulation, or pinched sections

4. 4

   Inspect the ECU pins and the actuator connectors for water ingress, corrosion, or bent pins that could bridge a power circuit to a ground/signal circuit

5. 5

   Test the resistance of the suspected actuator (e.g., relay, metering unit) to ensure it is not internally shorted

1. 1

   Turn off ignition and disconnect battery

   Turn off the ignition and disconnect the machine's battery to prevent further electrical damage.

2. 2

   Repair or replace wiring harness

   If the multimeter test reveals a short to battery in the wiring harness, locate the damaged section and repair the wires, or replace the affected harness section.

3. 3

   Replace actuator

   If the actuator is found to be internally shorted, replace the component.

4. 4

   Reconnect battery and clear codes

   Reconnect the battery, clear the fault codes using the Case IH Electronic Service Tool (EST), and cycle the ignition.

5. 5

   Replace or repair ECU

   If the wiring harness and all actuators test perfectly fine, the short circuit has likely permanently damaged the internal power stage hardware inside the ECU. In this case, the ECU must be replaced or sent to a specialized electronics repair facility (such as Bosch Electronic Service).