Case IH 19007 (DTC E6DE) - ECU – Engine Control Unit (ECU): NH3 sensor open or short in measuring cell circuit

This code indicates an internal open load or short circuit error on the measuring cell line of the NH3 (Ammonia) sensor. The NH3 smart sensor communicates with the engine controller via the CAN bus to provide measured signal values (NH3 and O2), status information, and hardware diagnostics. When the controller detects an electrical failure specifically within the NH3 measurement cells, it logs this fault.

• MAXXUM T4E
• 240 Series Axial-Flow Combines (5130, 7240, 8240, 9240)
• Puma series
• Maxxum 115
• Farmall 110U
• T7 Series (Tier 4B)
• Case N-Series TLBs (Tier 4 Final)
• 580N Backhoe Loaders

1. 1

   Inspect the NH3 sensor wiring harness and connectors for any broken, chafed, or disconnected wires.

2. 2

   Check the wiring for the correct voltage supply to the connected sensor.

3. 3

   Verify the CAN line connection from the EDC to the network. Ensure there is no short circuit in the wiring that could cause a timeout error on the CAN line corresponding to the NH3 sensor.

4. 4

   Look for accompanying codes like 19008 (E7DE - short in ground circuit) or 19009 (short in heater circuit) to isolate the exact circuit failure.

1. 1

   Turn off machine and disconnect battery

   Turn off the machine and disconnect the battery to ensure safety while working on the exhaust/emissions system.

2. 2

   Locate NH3 sensor

   Locate the NH3 sensor on the exhaust system (typically mounted downstream near the SCR catalyst).

3. 3

   Inspect wiring harness and pins

   Disconnect the wiring harness from the NH3 sensor and inspect the pins for corrosion or damage.

4. 4

   Replace NH3 sensor

   If the wiring and CAN network tests pass but the fault remains active, the internal measuring cell of the sensor has failed. The official repair action is to replace the defective NH3 sensor.

5. 5

   Install new sensor

   Install the new NH3 sensor and torque it to OEM specifications.

6. 6

   Reconnect and clear codes

   Reconnect the wiring harness, reconnect the battery, and use a diagnostic tool to clear the ECU fault codes.

7. 7

   Verify repair

   Run the engine to operating temperature to verify the code does not return. (Note: In rare cases where communication fails entirely after sensor replacement, the ECU software may need to be reflashed or the control unit replaced).