P2055
Reductant Injection Valve Circuit High Bank 1 Unit 2
Diesel exhaust / SCR (DEF)
Generic OBD-II
Medium
What it means
P2055 means the reductant (diesel exhaust fluid / DEF) injection valve circuit on bank 1, unit 2 is reading high — typically an open or short-to-voltage in the injector circuit, or a failed injector. This second DEF injector meters fluid into the SCR exhaust to cut NOx, so a fault reduces emissions control and may bring on SCR warnings and a power derate.
Medium
Can I keep driving? Drivable short-term, but expect SCR warnings and a possible power derate until the DEF injector circuit is repaired.
Common symptoms
What you'll notice
- Check-engine light on
- SCR / DEF or exhaust-system warning message
- Possible reduced power or emissions derate
Common causes
Most likely first
- Faulty reductant (DEF) injection valveLikely
- Open or short-to-voltage in the injector wiringCommon
- Corroded or loose connector at the injectorCommon
- Failed reductant control module / PCM (rare)Less often
How to diagnose & fix
Work through it in order
- Scan freeze-frame and note any companion SCR/DEF codes.
- Inspect the injector connector and wiring for opens or shorts to voltage.
- Measure the injector's resistance against spec.
- Replace the DEF injection valve if it's out of range; check for clogging or crystallized deposits.
- Clear the code and re-test with a drive cycle.
FAQ
Quick answers
Is it safe to drive with P2055?+
For a short time, yes, but the second DEF injector isn't dosing correctly, so NOx control suffers and the vehicle may begin a power derate. Repair it soon.
Can I just clear P2055?+
It returns until the injector or wiring is repaired, since the circuit keeps reading high. Fix the electrical fault first.
Related codes
Often seen with P2055
Read & clear P2055 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX