Case IH 1803 – ISM-IDI Engine Controller: DPF Exhaust Temperature Sensor Out Of Range High

The DPF OUT (Exhaust) Temperature Sensor is sending a voltage signal that is higher than the maximum allowed threshold ("Out of Voltage - High"), indicating the sensor has failed, there is an open circuit, or there is a short to power in the sensor's wiring harness.

• skid steer
• Skid Steer Loaders (SR175)
• Compact Track Loaders
• Tractors (Steiger, Farmall)

1. 1

   Inspect the wiring harness leading to the DPF OUT temperature sensor for chafing, melting from exhaust heat, or breaks.

2. 2

   Disconnect the sensor and check the connector pins for corrosion, moisture, or pushed-out terminals.

3. 3

   Use a multimeter to check the sensor circuit for an open circuit or a short to a 5V/12V power supply.

4. 4

   Use the Case IH Electronic Service Tool (EST) to monitor the live voltage and temperature readings of the DPF OUT sensor. An impossibly high temperature on a cold engine indicates a sensor or circuit fault.

5. 5

   Ensure there are no severe exhaust leaks or physical DPF blockages that could cause abnormal exhaust system behavior.

1. 1

   Prepare machine

   Turn off the engine, engage the parking brake, and disconnect the battery.

2. 2

   Cool exhaust system

   Allow the exhaust system to cool completely to avoid severe burns.

3. 3

   Locate sensor

   Locate the DPF OUT temperature sensor. It is threaded into the exhaust piping immediately downstream of the Diesel Particulate Filter.

4. 4

   Disconnect sensor

   Disconnect the electrical connector from the sensor.

5. 5

   Apply penetrating oil

   Apply penetrating oil to the base of the sensor threads and allow it to soak (exhaust sensors frequently seize due to extreme heat cycles).

6. 6

   Remove faulty sensor

   Using the appropriate wrench or sensor socket, carefully unscrew and remove the faulty sensor.

7. 7

   Apply anti-seize

   Apply a small amount of anti-seize compound to the threads of the new sensor (if not already pre-applied from the factory), being careful not to get any on the sensor probe itself.

8. 8

   Install new sensor

   Thread the new sensor into the exhaust pipe and tighten to the OEM torque specification.

9. 9

   Reconnect wiring

   Reconnect the electrical connector and secure the wiring harness away from direct heat sources.

10. 10

    Verify repair

    Reconnect the battery, connect the EST diagnostic tool, clear the fault codes, and run the machine (or perform a forced regeneration) to verify the sensor is reading within normal parameters.