OBD-II code · Powertrain (generic, extended)
P2ACE Reductant Temperature Sensor B Circuit Low
Voltage on the reductant temperature B sensor signal line is below the expected window. Wire shorted to ground or sensor short.
Is it safe to drive with P2ACE?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to ground
- PossibleInternal sensor short
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Temperature Sensor B, Wiring Harness, Ecm
Related codes
- P2044Reductant Temperature Sensor A Circuit Low
- P2ACBCharge Air Cooler Coolant Temperature Sensor B Circuit Intermittent/Erratic
- P2ACCReductant Temperature Sensor B Circuit
- P2ACDReductant Temperature Sensor B Range/Performance
- P2ACFReductant Temperature Sensor B Circuit High
- P2AD0Reductant Temperature Sensor B Circuit Intermittent/Erratic
- P2AD1Throttle/Pedal Position Sensor/Switch C/G Voltage Correlation
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.