New Holland 2046 – ECM / PCM / ACM: Reductant Temperature Sensor Circuit Intermittent

The Engine Control Module (ECM) has detected an intermittent, erratic, or implausible signal from the reductant (DEF) temperature sensor. This sensor measures the temperature of the Diesel Exhaust Fluid within the tank, which is critical for the Selective Catalytic Reduction (SCR) system to prevent freezing and properly convert NOx emissions. An intermittent signal indicates a temporary loss of communication or an unstable reading, typically caused by wiring faults, a failing sensor, or control module issues.

• T6
• T7
• T8
• T9
• CR Combine
• CX Combine
• 10.90X
• 11.90X
• 7030L
• 7030M
• 8030L
• C345

1. 1

   Visually inspect the wiring harness and connectors from the DEF tank reductant temperature sensor to the control module for chafing, burns, or corrosion

2. 2

   Check for applicable Technical Service Bulletins (TSBs) or software updates that might resolve known glitches

3. 3

   Use a diagnostic scan tool (like New Holland EST or Jaltest) to monitor live data from the reductant temperature sensor, watching for erratic behavior or signal dropouts

4. 4

   Perform a continuity test on the wiring harness with the sensor unplugged

5. 5

   Test the internal resistance of the sensor against manufacturer specifications, gently tapping it to check for intermittent internal failures

1. 1

   Repair wiring and connectors

   If diagnostic checks reveal damaged wiring or corroded connectors, repair or replace them. Ensure all connections are clean and secure, and apply dielectric grease to prevent future corrosion.

2. 2

   Replace reductant temperature sensor

   If the sensor fails resistance testing or shows erratic live data, replace it. Note that this is often part of a combined DEF tank sensor unit and usually requires removing or lowering the DEF tank to access.

3. 3

   Reprogram or replace ECM

   If the sensor and wiring are intact but the fault persists, the issue may lie within the Engine Control Module. Reprogram the ECM with the latest software or replace it if internal corrosion is found.

4. 4

   Clear codes and verify

   Use a diagnostic tool to clear the fault code. Operate the machine through various engine conditions to ensure the SCR system is functioning correctly and the code does not return.