Case IH 19765 – Engine Control Module (ECM): Monitoring of Pressure Asymmetric Build Up error

The system has detected an uneven, irregular, or asymmetric accumulation of pressure during its monitoring cycle, directly related to the engine's exhaust aftertreatment system (specifically the SCR/DEF dosing system or the DPF differential pressure system).

• Tier 4b
• Puma Series 115
• Puma Series 125
• Puma Series 130
• Puma Series 140
• Puma Series 145
• Puma Series 150
• Puma Series 155
• Puma Series 160
• Puma Series 165
• Puma Series 170
• Puma Series 180
• Puma Series 185
• Puma Series 195
• Puma Series 200
• Puma Series 210
• Puma Series 215
• Puma Series 220
• Puma Series 230
• Quantum Series 65
• Quantum Series 75
• Quantum Series 85
• Quantum Series 95

1. 1

   Visually inspect the SCR decomposition tube and the DEF doser for urea crystallization or deposits, which can restrict flow and cause asymmetric pressure readings.

2. 2

   Test the pressure sensor circuits (including the DPF differential pressure sensor and DEF pressure lines) for a short to ground or open circuit.

3. 3

   Check if there is a software or calibration update available for the ECM, as pressure monitoring logic is sometimes updated by the OEM.

1. 1

   Remove and Inspect

   Remove the SCR decomposition tube and inspect the area around the DEF doser for deposits.

2. 2

   Clean

   Thoroughly clean the pipe, the doser nozzle, and all mating surfaces to remove any urea build-up.

3. 3

   Reassemble

   Reinstall the decomposition tube and doser using all new clamps and gaskets to ensure there are no pressure leaks.

4. 4

   Sensor Replacement

   If the pressure asymmetry is traced to the exhaust side and the DPF differential pressure sensor is malfunctioning or reading erratically, remove and replace the sensor.

5. 5

   Verification

   Back the unit out of the shop and perform a parked regeneration. Monitor the system to confirm the repair is successful and that fault code 19765 remains inactive.