P2044Reductant Temperature Sensor A Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2044 is set when the signal of reductant temperature sensor A sits below its valid voltage window. As with other NTC thermistors, a low voltage corresponds to a hot reading, so a signal wire touching ground makes the fluid look extremely hot. Deutz lists P2044-00 as a grounded signal of the SCR-side DEF temperature input (SPN 4337) on the EMR L1 main and secondary ECU, kept apart from the tank sensor, whose low fault is P205C. No public table gives voltage or time limits for P2044; CARB only requires out of range and circuit checks for every input that feeds an emission control (13 CCR 1968.2 (f)(15.2.1)). A false hot value can switch off DEF heating in the cold, so frozen lines may follow. Measure the sensor and look for chafing before replacing parts.
- What you may notice
- MIL and DEF warning
- Scan tool shows an implausibly high DEF temperature
- Lines may freeze because heating stays off
- Likely causes
- LikelySignal wire chafed through to ground
- PossibleSensor shorted internally (resistance near zero)
- PossibleDEF residue in the connector bridging signal and ground
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.