Case IH 3682 – Engine Control Unit (ECU) / EDC (Electronic Diesel Control): Exhaust temperature : Fault Check for enhanced SRC-Max of First exhaust gas temperature.

This code indicates that the signal from the First Exhaust Gas Temperature (EGT) Sensor has exceeded the maximum allowable threshold (SRC-Max). In electrical terms, this almost always points to an open circuit or a short circuit to a higher voltage (battery/power) in the sensor itself or its wiring harness.

• Farmall 100C
• Farmall 105A
• Farmall 105C
• Farmall 105U
• Farmall 110A
• Farmall 110C
• Farmall 110U
• Farmall 115A
• Farmall 115C
• Farmall 115U
• Farmall 120U
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 140
• Puma 140
• Axial-Flow 5130
• Axial-Flow 5140
• Axial-Flow 7130
• Axial-Flow 7140
• Axial-Flow 7150
• Axial-Flow 7230
• Axial-Flow 7240
• Axial-Flow 7250
• Axial-Flow 9230

1. 1

   Visually inspect the first exhaust gas temperature sensor wiring harness for chafing, melting, or breaks.

2. 2

   Disconnect the EGT sensor and check the pins on both the sensor and harness sides for corrosion, pushed-out pins, or moisture intrusion.

3. 3

   Using a multimeter, check the harness side for a short to battery voltage or an open ground circuit.

4. 4

   Measure the resistance across the pins of the EGT sensor; an 'OL' (Open Loop) or infinite resistance reading indicates internal sensor failure.

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Locate the Sensor

   Identify the EGT Sensor 1 on the exhaust system. Ensure the exhaust system has completely cooled down before attempting removal to prevent severe burns.

3. 3

   Disconnect

   Unplug the electrical connector from the EGT sensor.

4. 4

   Remove the Sensor

   Using an appropriate line wrench or EGT sensor socket, carefully loosen and remove the faulty sensor from the exhaust pipe. Note: If the sensor is seized, apply penetrating oil and allow it to soak to prevent stripping the exhaust bung threads.

5. 5

   Prepare the New Sensor

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor (if it does not already come with pre-applied thread paste). Do not get any anti-seize on the sensor probe itself.

6. 6

   Install

   Thread the new sensor into the exhaust bung by hand to prevent cross-threading, then tighten to the OEM torque specification.

7. 7

   Reconnect

   Plug the electrical connector back into the engine wiring harness. Ensure it clicks and locks securely.

8. 8

   Clear Codes

   Reconnect the battery, turn the key to the ON position, and use a diagnostic scan tool (like the Case IH EST) to clear the inactive 3682 fault code.

9. 9

   Test Run

   Start the engine and allow it to reach operating temperature to verify the code does not return and that the ECU is reading plausible exhaust temperatures.