P208B code meaning
Reductant Pump A Control Performance/Stuck Off
Powertrain system Generic code P20xx codes Check engine light
What P208B means
P208B is the functional check of DEF pump A: the circuit is intact, yet the pump ignores its command or stays off. Ford, titling it Reductant Pump Control Range/Performance, sets it on 2023 diesels when pump speed misses its setpoint by over 300 rpm or its speed control sits at a limit for 30 s, detected within 5 s and only after the circuit tests have passed. GM's 2014 diesel table reports Reductant Pump Performance when the pump motor's functional acknowledgement takes longer than 4 s, Type B. Deutz EMR5 adds an overheated output stage (P208B-4B) and an abnormal rate of change (P208B-92). In the field the hydraulics are usually to blame: FCA STAR S1925000008 (Grand Cherokee, Wrangler diesel) names trapped air in the tank filter and external leaks, and a Volkswagen 2.0 TDI tip rules out leaking lines first.
P208B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P208B
- MIL with DEF system message, often with P20E8
- White urea crust on lines or fittings
- Countdown to no-restart or reduced power
Common causes of P208B
- Most likelyAir trapped in the tank filter or suction side after service
- Most likelyLeaking DEF line or connection between pump and dosing valve
- PossibleWorn, frozen or crystallised pump
- Less likelyCalibration needing an update (FCA 3.0L diesel)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant pump
What each part of P208B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 8B | The exact fault in that area. |
What to do next
- Note P208B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P208B
What does P208B mean?
P208B means "Reductant Pump A Control Performance/Stuck Off". P208B is the functional check of DEF pump A: the circuit is intact, yet the pump ignores its command or stays off. It is a generic code, so it means the same on every make.
Is it safe to drive with P208B?
Drive gently and only to a workshop. With P208B the car can go into limp mode (reduced power) to protect itself.
Will P208B fail an emissions test?
Yes, it can. P208B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P208B to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P208B clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.