What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P203BReductant Level Sensor 1 Circuit PerformanceP203BReductant Level Sensor Circuit PerformanceManufacturer communications
5Original wording in English
RAM
Reported code forms P203B
Flash: Dosing Control Unit (DCU) Diagnostic and System Improvements This bulletin involves reprogramming the DCU with the latest available software and if necessary replacing the unit. Some customers may experience a…
RAM
Reported code forms P203B
Flash: Dosing Control Unit (DCU) Diagnostic And System Improvements This bulletin involves reprogramming the DCU with the latest available software and if necessary replacing the unit. Some customers may experience a…
RAM
Reported code forms P203B
Diesel Exhaust Fluid (DEF) Level Sensor Manufacturing Defect This bulletin involves replacing the DEF pump module. A manufacturing defect in the level sensor may have occurred, if the level sensor was built within the…
RAM
Reported code forms P203B
Diesel Exhaust Fluid (DEF) Level Gauge Inaccurate Or Stuck This bulletin involves verifying the correct DEF level in the tank and if necessary, replacing the DEF pump module. A small number of customers may comment that…
RAM
Reported code forms P203B
Diesel Exhaust Fluid (DEF) Level Gauge Inaccurate Or Stuck This bulletin involves verifying the correct DEF level in the tank and if necessary, replacing the DEF pump module. A small number of customers may comment that…
Check vehicle applicability
3A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.