P2045Reductant Temperature Sensor A Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2045 covers the opposite end: the voltage of reductant temperature sensor A is higher than any real temperature would produce. With an NTC element this reads as very cold, which is what an interrupted ground, a disconnected plug or a signal wire touching battery voltage cause. Deutz files P2045-00 as a short to battery for the DEF sensor outside the tank (SPN 4337); an open circuit gets its own entry, P2042-13. The tank temperature sensor counts separately, with its high fault under P205D. As no maker publishes thresholds for P2045, the CARB rule on input circuit monitoring (section (f)(15.2.1) of 13 CCR 1968.2) is the frame. A false cold value may keep the heater running and delay dosing after start. Check the plug, the ground and the sensor resistance at a known temperature.
- What you may notice
- MIL and DEF warning
- Scan tool shows DEF temperature near the lower limit
- Dosing may start late after a cold start
- Likely causes
- LikelyOpen sensor ground or unplugged connector
- PossibleSignal wire shorted to battery or supply voltage
- PossibleSensor element open internally
- 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.