Case IH 272 – Engine Control Module (ECM): Front Pumping Control Valve current is high

The Engine Control Module (ECM) has detected a short circuit (excessive current draw) in the electrical circuit controlling the front pumping control valve. This valve is a critical component of the Cummins CAPS fuel injection pump, and its failure typically causes the engine to enter a derated 'low power' mode.

• MX Magnum
• STX Steiger
• MX Magnum Series
• TG Series
• Steiger
• Puma series
• Axial-Flow combines

1. 1

   Disconnect the engine harness from the front pumping control valve at the four-pin connector on the CAPS pump to perform a visual inspection.

2. 2

   Inspect the front pumping valve four-pin connector and terminals for bent or broken pins, pushed back or expanded pins, corroded pins, moisture inside the connector, or missing/damaged weather seals.

3. 3

   Test the wiring harness between the CAPS pump and the Engine ECM for a short circuit. The front pumping control valve return circuit corresponds to Pin A21 on the Engine ECM.

4. 4

   Use the machine's diagnostic menu to perform a 'click test' on the pumping control valves to see if the ECM can successfully actuate the solenoid without tripping the high-current fault.

1. 1

   Disconnect power

   Turn off the key switch and disconnect the battery to prevent electrical spikes.

2. 2

   Clean pump exterior

   Thoroughly clean the exterior of the CAPS fuel injection pump and surrounding engine area. The CAPS system is highly sensitive to dirt and debris.

3. 3

   Disconnect connector

   Disconnect the four-pin electrical connector from the pumping control valve assembly.

4. 4

   Measure resistance

   Using a multimeter, measure the resistance across the pins for the front pumping control valve on the pump side. A reading of near-zero ohms confirms an internal short circuit in the coil.

5. 5

   Remove failed module

   Depending on part availability, remove the failed CAPS accumulator module / stator assembly from the top of the injection pump. (Note: The valve close angle must not vary more than 15 degrees between the front and rear valves; if it does, the entire accumulator module must be replaced).

6. 6

   Install new module

   Install the new pumping control valve/accumulator module using new O-rings lubricated with clean engine oil.

7. 7

   Reconnect and clear codes

   Reconnect the four-pin harness, reconnect the batteries, and clear the inactive fault codes from the ECM.

8. 8

   Prime fuel system and test

   Prime the fuel system (the electric lift pump will run for 30-60 seconds when the key is turned on) and start the engine to verify that full power is restored and the code does not return.