Case IH 392 – ENG: Engine Brake driver 2 circuit failure

An electrical fault in the signal circuit for the number 2 engine brake actuator/solenoid. The Engine Control Module (ECM) has detected that the circuit is either experiencing an open circuit, a short to ground (voltage below normal), or a short to a high voltage source (voltage above normal), preventing the engine brake on the corresponding cylinders from being activated.

• MX Magnum
• STX Steiger
• Steiger
• Magnum
• Puma
• Puma 125
• T7 series
• TM 175
• CR9090
• CX8080/CX8090 Elevation Tier 4A

1. 1

   Read active codes to verify if the code is active and check for related Cummins SPN/FMI codes (e.g., SPN 1073 FMI 3 or 4, Fault Codes 2363 or 2367)

2. 2

   Visually inspect the wiring harness connecting the Engine ECU to the #2 engine brake solenoid for chafed wires, melted insulation, or corrosion

3. 3

   Disconnect the harness at the ECM and the engine brake solenoid to check for loose, bent, or pushed-back pins

4. 4

   Use a multimeter to test the #2 engine brake signal circuit for continuity, short to ground, and short to power

5. 5

   Measure the resistance of the #2 engine brake solenoid to determine if the internal coil has failed open or shorted

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the battery to prevent electrical spikes during repair.

2. 2

   Access the Solenoid

   Remove the engine valve cover to access the engine brake solenoids (jake brake actuators), which are mounted on the valvetrain under the cover.

3. 3

   Isolate the Fault

   Based on your multimeter diagnostics, isolate whether the failure is in the engine wiring harness or the solenoid itself.

4. 4

   Replace the Component

   If the wiring harness is damaged, repair the broken wire or replace the affected harness section. If the solenoid fails the resistance test (open coil), unbolt the faulty #2 engine brake solenoid and install a replacement.

5. 5

   Reassembly

   Reinstall the valve cover with a new gasket. Reconnect the battery.

6. 6

   Clear Codes

   Use a diagnostic tool (such as a Can-Bus emulator or dealer diagnostic tool) to clear the ENG 392 fault code from the ECM.

7. 7

   Test Operation

   Run the engine and test the engine brake operation to ensure the code does not return and all braking stages engage properly.