Deutz-Fahr 110 – ECM: ECT Sensor Circuit Break or Short

The Engine Control Module (ECM) has detected an electrical fault within the Engine Coolant Temperature (ECT) sensor circuit (SPN 110). This indicates either a cable break (open circuit) or a short circuit in the wiring. Because the ECM relies on the coolant temperature reading for critical functions such as engine protection, fuel injection timing, and cooling fan control, this fault can lead to improper operation or failure of the connected components.

• Deutz 1011
• Deutz 2011
• Deutz TCD 2.9
• Deutz TCD 3.6
• Deutz TCD 4.1
• Deutz TCD 6.1
• Deutz TCD 7.8

1. 1

   Visually inspect the coolant temperature sensor, its electrical connector, and the surrounding wiring harness for chafed wires, heat damage, or corrosion.

2. 2

   Ensure the sensor's electrical connector is fully seated and locked, as a loose connection can cause intermittent faults.

3. 3

   Check for multiple active fault codes, which may indicate a shared ground or reference voltage wire issue rather than a single component failure.

4. 4

   Disconnect the sensor and turn the ignition ON (engine off). Verify a 5-volt reference signal at one pin of the harness connector and a good ground connection at another.

5. 5

   With the sensor disconnected, measure for continuity between the signal wire and battery positive (checking for a short to voltage) and between the signal wire and ground (checking for a short to ground). If a short persists with the sensor disconnected, the fault is in the wiring harness. If the short only appears when the sensor is connected, the sensor itself is internally shorted.

6. 6

   Test the sensor resistance across its terminals with the engine cold. Compare to manufacturer specifications (e.g., 30k-36k ohms at 0°C, 9k-11k ohms at 25°C). If out of spec, the sensor is internally faulty.

1. 1

   Wiring Harness Repair: Isolate the fault

   If the diagnostic checks indicate a fault in the wiring harness (e.g., a short or open circuit), locate the damaged section.

2. 2

   Wiring Harness Repair: Repair or replace

   For minor damage, carefully repair the wire using appropriate splicing techniques and seal the repair with heat-shrink tubing. For extensive damage, replacing the entire engine harness section may be necessary using Deutz wiring harness repair kits.

3. 3

   Wiring Harness Repair: Clear codes

   After the repair, clear the fault codes using a diagnostic tool and verify that the fault does not return.

4. 4

   Sensor Replacement: Prepare the vehicle

   Ensure the engine is completely cool to prevent burns. Park on a level surface, place a drain pan under the sensor's location, and disconnect the negative battery terminal.

5. 5

   Sensor Replacement: Locate and remove the sensor

   Clean the area around the sensor. Disconnect the electrical connector gently to avoid breaking the locking tab. Using a deep socket or wrench, carefully unscrew the old sensor.

6. 6

   Sensor Replacement: Install the new sensor

   If required, apply a suitable thread sealant to the threads. Hand-thread the new sensor, then tighten it to the manufacturer's specified torque (typically under 20 lb-ft). Reconnect the electrical connector, ensuring it clicks into place.

7. 7

   Sensor Replacement: Final steps

   Top off the cooling system with the correct type of coolant. Reconnect the battery, start the engine, and check for any leaks around the new sensor. Allow the engine to reach operating temperature and clear any stored fault codes.