Case IH 19199 (F-171-02) - ECU – Engine Control Unit (ECU): Plausibility check error of the third fresh air temperature sensor at cold start

During a cold engine start, the control unit monitors up to five temperature sensors for mutual plausibility. This code is triggered when the reading from the third fresh air temperature sensor (which is integrated into the intake manifold boost pressure and temperature sensor) is implausible compared to the other temperature sensors on the engine.

• VESTRUM CVX
• Austoft 9900 Sugarcane Harvesters
• T7 Series Tractors
• Other Case IH and New Holland machines sharing the FPT Cursor engine architecture

1. 1

   Turn the ignition switch to the OFF position.

2. 2

   Locate the intake manifold temperature and pressure sensor (identified in schematics as Sensor B-FPT-48).

3. 3

   Disconnect the sensor and use a multimeter to check the resistance at the sensor's receptacle connector (X-9325) between pin 1 and pin 3.

4. 4

   Verify the resistance: It should measure approximately 2.5 kΩ at 20.0 °C (68.0 °F).

5. 5

   Visually inspect the harnesses and connectors between the sensor and ECU A-028. Look for damaged, bent, or dislocated pins, corroded terminals, or broken wires.

6. 6

   Flex the involved wiring harnesses to reveal any intermittent breaks or shorts.

1. 1

   Replace the intake manifold temperature and pressure sensor.

   If the resistance measured at the sensor is not within the 2.5 kΩ specification at 20 °C, the sensor has failed internally. Replace the intake manifold temperature and pressure sensor.

2. 2

   Repair any harness or connector damage.

   If the sensor's resistance is within specification, the issue lies in the wiring or the ECU software. Repair any harness or connector damage discovered during the visual inspection.

3. 3

   Verify and update ECU software.

   If the wiring is intact and the sensor tests good, verify that the appropriate software version is present on ECU A-028. Reinstall or update the ECU software using the electronic service tool (EST) if necessary.

4. 4

   Clear the fault code and verify repair.

   Once the physical repair or software flash is complete, clear the fault code and operate the machine while observing the monitor to verify the error has been corrected.