Case IH 19479 – Engine Control Module (ECM / ECU): Short circuit to battery error at the Low Side of Exhaust flap powerstage

The engine's control module has detected a short circuit to a voltage source (battery) or an open circuit on the low side of the electrical power stage that controls the exhaust flap actuator.

• Tier 4b
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380 CVT
• Steiger 470
• 240 Series Combines
• CR/CX Series Combines
• 821F Wheel Loader
• 921F Wheel Loader

1. 1

   Check the exhaust flap actuator supply and wiring harness for a short circuit to the battery, chafing, or an open circuit/disconnected cable.

2. 2

   Inspect the exhaust flap mechanically for binding or sticking caused by soot buildup, increased friction, or high mechanical load.

3. 3

   Verify the presence and correct connection of the Exhaust Flap Actuator to the CAN network, checking for undervoltage or a missing CAN controller signal.

4. 4

   Perform a power-up test using the FPT Engine Troubleshooting software to see if the exhaust flap gets stuck during the ECM's automated test.

1. 1

   Connect Diagnostic Tool

   Connect the CNH EST diagnostic tool and open the FPT Engine Troubleshooting software to read and save all active fault codes.

2. 2

   Inspect and Repair Wiring

   Trace the wiring harness from the ECM to the exhaust flap actuator. If a short circuit to the battery or an open wire is found, repair or replace the wire harness as required.

3. 3

   Replace Actuator/Flap

   If the wiring is intact and the flap is not mechanically seized by soot, the exhaust flap actuator's internal power stage is defective. Replace the exhaust flap valve/actuator assembly.

4. 4

   Reset Inducement Counters

   Because this is an emissions-related fault, the engine may have entered a torque derate (performance limitation). In the FPT software, click on "INDUCEMENT COUNTER RESET FOR SERVICE".

5. 5

   Cycle Ignition

   Turn the ignition switch ON, click the green tick in the software, then turn the ignition switch OFF and click the green tick again to finalize the reset.

6. 6

   Drive Cycle

   Complete the required driving cycles to heal the code and verify the repair was successful.