Case IH 1804 – Engine Control Unit (ECU) / ISM-IDI: ISM-IDI High DPF Intake temperature

The exhaust gas temperature entering the Diesel Particulate Filter (DPF) has exceeded the maximum safe operating threshold. This condition is typically caused by a failing Exhaust Gas Temperature (EGT) sensor reading out of range (Signal Above Range Max), excessive unburned fuel entering the exhaust system (such as from leaking fuel injectors), or a severe restriction/clog in the DPF.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Farmall (100C to 140A)
• Maxxum (120 to 150)
• Puma (130 to 240)
• Optum (270 to 300)
• Steiger (350 to 620)
• Quadtrac (370 to 620)
• Rowtrac (420 to 500)
• Combine 5130
• Combine 5140
• Combine 7130
• Combine 7140
• Combine 7230
• Combine 7240
• Combine 9230
• Combine 9240

1. 1

   Check for Concurrent Codes: Use the Electronic Service Tool (EST) to check for other active fault codes. Codes related to fuel rail pressure or injection timing could indicate leaking injectors causing the high exhaust temperatures.

2. 2

   Live Data Monitoring: Monitor the DPF intake temperature sensor via the EST. If the sensor reads 'Signal Above Range Max' when the engine is cold, the sensor itself is likely shorted or faulty.

3. 3

   Wiring Inspection: Inspect the sensor's wiring harness and the 2-pin Bosch connector for melting, chafing, corrosion, or shorts to ground/power.

4. 4

   Physical Inspection: Check the DPF for heavy soot accumulation or physical blockages that could be trapping heat.

1. 1

   Safety First

   Turn off the machine, disconnect the battery, and allow the exhaust system to cool completely. The DPF and surrounding components operate at extremely high temperatures.

2. 2

   Locate the Sensor

   Locate the Exhaust Gas Temperature (EGT) sensor on the exhaust pipe at the intake side of the DPF housing.

3. 3

   Disconnect Wiring

   Unplug the 2-pin Bosch electrical connector from the machine's wiring harness.

4. 4

   Remove the Sensor

   Using a wrench, carefully unscrew the sensor from the exhaust housing. The sensor uses an M14x1.5 thread. Apply penetrating oil if the sensor is seized from heat cycling.

5. 5

   Install the New Sensor

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor (if not pre-applied). Thread it into the housing and tighten to the OEM torque specification.

6. 6

   Reconnect

   Plug the 2-pin connector back into the wiring harness and reconnect the battery.

7. 7

   Clear Codes and Test

   Use the EST to clear fault code 1804. Start the engine and initiate a stationary/forced DPF regeneration to verify that the temperature readings are now within normal limits and the code does not return.