Case IH 484 – Engine Control Module (ECM): Rear Bank Post Actuator Pressure voltage low

The Engine Control Module (ECM) has detected that the voltage signal from the Rear Bank Post Actuator Pressure Sensor is abnormally low. A low voltage condition typically indicates a short circuit to ground in the wiring harness, a loss of the 5-volt reference supply, or an internal failure of the sensor itself.

• MX Magnum
• STX Steiger
• Case IH Steiger series tractors
• Case IH Magnum series tractors
• Case IH Puma series tractors

1. 1

   Inspect the wiring harness leading to the Rear Bank Post Actuator Pressure Sensor for chafing, bare wires, or moisture intrusion.

2. 2

   Disconnect the sensor and inspect the connector pins for corrosion, pushed-back pins, or damage.

3. 3

   With the keyswitch ON (engine off), use a multimeter to verify that the sensor is receiving a 5-volt reference supply from the ECM.

4. 4

   Check the signal wire circuit for continuity to ground. If continuity is found where it shouldn't be, the harness is shorted.

1. 1

   Power down ECM

   Turn the ignition keyswitch to the OFF position and allow the ECM to power down completely.

2. 2

   Locate sensor

   Locate the Rear Bank Post Actuator Pressure Sensor on the Integrated Fuel System Module (IFSM) or fuel rail assembly.

3. 3

   Disconnect harness

   Disconnect the engine harness from the sensor.

4. 4

   Repair wiring harness

   If the diagnostic checks revealed a short to ground in the wiring, repair the damaged section of the engine harness or replace the harness pigtail.

5. 5

   Remove faulty sensor

   If the wiring harness and 5-volt supply test OK, the sensor has failed internally. Unthread and remove the faulty pressure sensor.

6. 6

   Install new sensor

   Install the new pressure sensor and tighten it to the OEM torque specification.

7. 7

   Reconnect harness

   Reconnect the electrical harness to the sensor, ensuring the locking tab clicks into place.

8. 8

   Connect service tool

   Turn the keyswitch ON and connect your electronic service tool (CNH EST or Cummins INSITE).

9. 9

   Clear codes and verify repair

   Clear the inactive fault codes. Start the engine and verify that the fault code does not return and that the engine operates smoothly on all cylinders.