Case IH 19671 – VCM (Vehicle Control Module) / Engine ECU: Plausibility defect between Turbine downstream pressure sensor and environmental pressure

The engine control system has detected a static plausibility error. The reading from the turbine downstream pressure sensor does not match the reading from the environmental (ambient/barometric) pressure sensor at key-on, engine-off (KOEO).

• Tier 4b
• Case N-series TLBs

1. 1

   Perform a static plausibility check using an electronic service tool at key-on, engine-off (KOEO) to compare Turbine Downstream Pressure and Environmental Pressure.

2. 2

   Evaluate the sensor for calibration drift or exhaust leakage around the mounting.

3. 3

   Inspect the wiring harness and connector for the turbine downstream pressure sensor for shorts to battery/ground or open circuits.

4. 4

   Inspect the exhaust gas pressure sensor signal tube and port for heavy soot buildup or blockages.

1. 1

   Power Down

   Turn off the machine and turn the keyswitch to the ON position (do not start the engine) to connect your electronic service tool.

2. 2

   Verify Sensor Data

   Read the current data for both the environmental pressure and the turbine downstream pressure to confirm the plausibility deviation.

3. 3

   Inspect Wiring

   Disconnect the turbine downstream pressure sensor. Inspect the pins for corrosion and the harness for chafing or shorts.

4. 4

   Remove and Inspect Sensor/Tube

   Remove the exhaust gas pressure sensor and its signal tube from the exhaust manifold/pipe. Clean any carbon or soot blockages from the tube and the mounting port.

5. 5

   Replace Sensor

   If the wiring is intact, the port is clear, and the sensor reading is still drifted/implausible, the sensor itself has failed internally and must be replaced.

6. 6

   Reassembly

   Install the new sensor (and new gaskets if the signal tube was removed) and torque the mounting hardware to OEM specifications.

7. 7

   Clear Codes

   Reconnect the electronic service tool, clear the 19671 fault code, and verify that the sensor readings now match at key-on, engine-off.