P2ADD
Reductant Tank Temperature Sensor B Circuit Intermittent/Erratic
The reductant tank B temperature sensor signal drops out or jumps intermittently. Loose connector or noisy ground.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
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)
Common causes
Ordered by how often each turns out to be the cause.
- Sensor connector not seatedCommon
- Noisy ground referencePossible
- Connector with intermittent contact under vibrationLess likely
Parts involved
- Reductant Tank Temperature Sensor B
- Wiring Harness
- SCR Module
P2ADD is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.