P2055 Reductant injector: signal or voltage too high (unit 2, bank 1)
P2055 means: Reductant injector: signal or voltage too high (unit 2, bank 1). The AdBlue (SCR) system sprays a urea solution into the exhaust to reduce nitrogen oxides. Drive gently and have the car checked soon. The most common repair costs about €45–90 in Estonia, depending on make and model.
What it means
The AdBlue (SCR) system sprays a urea solution into the exhaust to reduce nitrogen oxides. The computer found a fault in the AdBlue quantity, quality, pump, injector or NOx sensor. The signal voltage is too high. Usually a wire is shorted to power, the ground is broken or the part itself has failed.
What you may notice
- AdBlue warning on the dashboard
- A countdown of km left before the car won't restart
- Engine light on
What could be wrong
- 1Connector loose, damp or corroded · Wiring or connector repair €45–90
- 2Wire shorted to power or ground broken · Wiring or connector repair €45–90
- 3Faulty sensor or dosing module · Sensor replacement €80–160
- 4Engine computer fault (rare) · Control unit check and software €150–300
Repair difficulty: Moderate
What you can check yourself
First look at the connector and wiring: anything loose, melted or green with corrosion? Check the AdBlue level and only fill with certified AdBlue. Don't ignore the warning: eventually the car won't start. You can check the simple things yourself, but the repair is best done in a workshop.
How we fix it
- We read the fault data on the diagnostic tool and check whether the fault is constant
- We measure the circuit's supply, ground and signal
- We repair the wire or replace the connector
- If the wiring is fine, we replace the sensor or dosing module
Standard SAE description: Reductant Injection Valve Circuit High Bank 1 Unit 2