Case IH 19202 (F-519551-02) - ECU – Engine Control Unit (ECU): Error in case of more than one not plausible fresh air temperature at cold start

During a cold start, the control module compares the readings of multiple engine temperature sensors (such as the intake air, ambient air, coolant, or EGR fresh air temperature sensors). If more than one of these sensors provides a reading that deviates significantly from the expected cold-engine baseline (an "implausible" signal), the system logs this fault.

• VESTRUM CVX
• Case IH Magnum AFS Connect series
• Case IH Farmall series
• Case IH Steiger series
• Case IH Maxxum series

1. 1

   Use a diagnostic scan tool to monitor all engine temperature sensors (Intake Air Temperature, EGR Fresh Air Temperature, Coolant Temperature) during a cold start to identify which sensors are reporting implausible or conflicting values.

2. 2

   Inspect the wiring harnesses and connectors linking the affected temperature sensors to the ECU for physical damage, short-circuits to ground or battery, open circuits, or high resistance.

3. 3

   Check the sensor supply voltage and ground circuits to ensure the sensors are receiving the correct voltage from the ECU.

1. 1

   Locate faulty sensors

   Locate the temperature sensors that failed the diagnostic plausibility check (commonly the Intake Air Temperature or EGR Fresh Air Temperature sensors).

2. 2

   Inspect wiring harness and pins

   Disconnect the wiring harness from the suspect sensor(s) and inspect the pins for corrosion or damage.

3. 3

   Repair wiring or connectors

   Repair any damaged wiring or connectors found during the diagnostic phase.

4. 4

   Replace temperature sensor

   If the wiring and voltages test good but the sensor reading remains implausible, remove and replace the faulty temperature sensor(s).

5. 5

   Clear fault codes

   Clear the fault codes from the ECU using a diagnostic tool.

6. 6

   Verify repair

   Perform a cold start to verify that the sensors now read plausibly and the fault code does not return.