Case IH ENG396 – ECU: Low Current in Rear Fueling Circuit

The Engine Control Unit (ECU) has detected an abnormally low electrical current in the circuit that controls the rear fueling or pumping element of the Cummins Accumulator Pump System (CAPS). This prevents the rear pumping element from drawing the expected electrical current, which compromises the proper operation of the rear fueling system and its ability to build and maintain the required fuel pressure.

• 7210
• 7220
• 7230
• 7240
• 7250
• 8910
• 8920
• 8930
• 8940
• 8950
• MX255
• MX285

1. 1

   Check for other active fault codes related to the CAPS pump (such as ENG 273, 274, 282, and 328), as they should be addressed concurrently

2. 2

   Inspect the fuel system for leaks, kinked lines, or restrictions like a clogged fuel filter or air in the system

3. 3

   Verify the electric fuel lift pump is functioning correctly and providing adequate fuel pressure to the CAPS pump

4. 4

   Inspect the wiring harness and connectors leading to the CAPS pump accumulator, specifically looking for damage, corrosion, or loose connections at the rear pumping element solenoid connector

5. 5

   Perform a 'click test' on the pumping element solenoids to verify their mechanical operation (failure to produce an audible click indicates a failed solenoid)

1. 1

   Disconnect battery

   Always disconnect the negative battery cable before working on the fuel system.

2. 2

   Access the CAPS pump

   Locate the CAPS pump on the engine. Remove any obstructing components if necessary to gain access to the accumulator module.

3. 3

   Test rear pumping element solenoid

   Using a multimeter, test the resistance of the rear pumping element solenoid. Compare the reading to the manufacturer's specifications. An out-of-range reading indicates a failed solenoid.

4. 4

   Test wiring harness

   If the solenoid tests within specification, check for continuity and for shorts to ground or power in the wiring harness between the ECU and the solenoid connector.

5. 5

   Replace faulty components

   If the solenoid is faulty, replace the accumulator module on top of the CAPS pump (which contains the solenoids). If the wiring is damaged, repair or replace the engine wiring harness.

6. 6

   Clear fault codes

   After repairs are complete, reconnect the battery and use a diagnostic tool to clear all fault codes.

7. 7

   Verify the repair

   Start the engine and let it run to ensure the fault code does not reappear. Operate the machine under normal conditions to confirm the repair is successful.