Case IH 3683 – Engine Control Module (ECM) / EDC: Exhaust temperature : Fault Check for enhanced SRC-Min of First exhaust gas temperature

The Engine Control Module has detected that the first Exhaust Gas Temperature Sensor (EGTS) upstream of the SCR catalyst is reporting a temperature that is below the minimum expected threshold during an enhanced system check. This prevents the SCR system from properly dosing DEF.

• Case IH Steiger
• Case IH Puma
• Case IH Magnum

1. 1

   Inspect the wiring harness and connector for the first exhaust gas temperature sensor for chafing, melted wires, corrosion, or loose pins.

2. 2

   Inspect the exhaust manifold and piping upstream of the sensor for a severe exhaust leak.

3. 3

   Use the CNH Electronic Service Tool (EST) to monitor the live data of the first exhaust gas temperature sensor and compare its reading to the second sensor and ambient temperature when cold.

4. 4

   Remove the sensor and inspect the probe tip for heavy soot accumulation or physical damage.

1. 1

   Preparation

   Turn off the machine, disconnect the battery, and allow the exhaust system to cool completely to avoid severe burns.

2. 2

   Locate the Sensor

   Locate the first exhaust gas temperature sensor on the exhaust pipe, positioned before the SCR catalytic converter.

3. 3

   Disconnect

   Unplug the sensor's electrical connector from the main engine harness.

4. 4

   Removal

   Using a suitable wrench (often 14mm or 17mm), carefully unscrew the sensor from the exhaust bung. Penetrating oil may be required if the sensor is seized.

5. 5

   Preparation of New Sensor

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor (if not pre-applied). Do not get any anti-seize on the sensor probe tip.

6. 6

   Installation

   Thread the new sensor into the exhaust bung by hand to prevent cross-threading, then tighten securely with a wrench.

7. 7

   Reconnect

   Route the sensor wire safely away from direct heat sources and reconnect the electrical connector, ensuring it clicks into place.

8. 8

   Clear Codes and Test

   Reconnect the battery, use the CNH EST diagnostic tool to clear the 3683 / 2F7 fault code, and start the engine to reach operating temperature (or initiate a stationary regeneration) to verify the new sensor is reading correctly.