U0619Lost Communication With Reductant Level Sensor A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- Reductant level sensor A reports how much diesel exhaust fluid (DEF, AdBlue) is left in the SCR tank. Newer tank units are smart sensors: a sensing element plus electronics that transmit level, temperature and often concentration as digital frames over CAN, SENT or LIN. U0619 means the engine or aftertreatment controller gets no valid frames from that level sensor, whether the line is silent, frames time out, checksums fail or the sensor flags an internal fault. CARB requires a digital input that stops talking to store its own code, apart from the circuit and plausibility codes P203A to P203E. No manufacturer publicly documents a detection rule for U0619. Without a level value the low-DEF warning is lost and the controller can no longer rule out an empty tank, which California treats as an SCR fault.
- What you may notice
- Check engine light or SCR warning
- DEF gauge blank or frozen at a fixed value
- No warning before the DEF tank runs empty
- Likely causes
- LikelyCorroded, water-soaked or loose connector at the DEF tank sensor
- PossibleData line, supply or ground of the tank sensor chafed or broken along the frame
- PossibleElectronics of the tank level sensor failed (often replaced as a tank sender unit)
- RareController software or configuration not matching the installed sensor
- 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: €80 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.