Case IH 19197 – VCM: Plausibility check error of the first fresh air temperature sensor at cold start

During a cold start, the control module compares the reading of the fresh air temperature sensor against other temperature sensors. If the fresh air temperature sensor reports a value that deviates significantly from the expected ambient baseline, the system flags it as implausible and logs this fault code.

• Tier 4b
• Case 580N
• Case 580SN
• Case 580SN WT
• Case 590SN

1. 1

   Allow the machine to sit overnight (cold soak) so all temperature sensors equalize to the ambient temperature

2. 2

   Use the Case Electronic Service Tool (EST) to monitor the live data for the first fresh air temperature sensor and compare it to other temperature sensors (e.g., engine coolant temperature, intake manifold temperature) to ensure they read within a few degrees of each other

3. 3

   Inspect the wiring harness and the connector at the fresh air temperature sensor for signs of corrosion, moisture, backed-out pins, or chafed wires that could cause resistance issues

4. 4

   Disconnect the sensor and measure its resistance with a multimeter, comparing the reading against the OEM resistance-to-temperature chart for the FPT 3.4L engine to determine if the sensor has drifted out of specification

1. 1

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical shorts.

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the first fresh air temperature sensor.

   Locate the first fresh air temperature sensor (typically mounted in the intake air stream, near the air filter housing or intake piping before the turbocharger).

3. 3

   Depress the locking tab and disconnect the electrical harness from the sensor.

   Depress the locking tab and disconnect the electrical harness from the sensor.

4. 4

   Carefully unthread or unclip the faulty sensor from the intake piping.

   Carefully unthread or unclip the faulty sensor from the intake piping.

5. 5

   Install the new fresh air temperature sensor.

   Install the new fresh air temperature sensor, ensuring any O-rings or seals are properly seated to prevent unmetered air leaks.

6. 6

   Reconnect the electrical harness until it clicks securely into place.

   Reconnect the electrical harness until it clicks securely into place.

7. 7

   Reconnect the battery.

   Reconnect the battery.

8. 8

   Connect the diagnostic tool, clear the 19197 fault code from the VCM, and verify that the live temperature reading now matches the ambient temperature.

   Connect the diagnostic tool, clear the 19197 fault code from the VCM, and verify that the live temperature reading now matches the ambient temperature.