P2051Reductant Injection Valve Circuit Low (Bank 2 Unit 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2051 reports a ground fault on the drive wire of the DEF injector assigned to Bank 2, unit 1. Like its siblings P2050 and P2052, it presupposes a twin-bank SCR system with a dedicated valve per exhaust branch, and no manufacturer publishes a calibration or bulletin for it. The comparable Bank 1 tests give an idea of the limits: GM's 6.6 L LML flags less than roughly 0.5 ohm to ground for 2 s, and Ford's 2023 diesel logic reacts to valve current above 1.6 A. Where the second branch's harness passes hot exhaust parts, damaged insulation is the first thing to inspect. CARB treats the valve as a monitored component; once the code sets, that branch stops dosing and its NOx conversion collapses.
- What you may notice
- MIL on
- Dosing on Bank 2 switched off
- Possible NOx efficiency code for Bank 2 later
- Likely causes
- LikelyInsulation melted or chafed near the Bank 2 exhaust
- PossibleShorted coil in the Bank 2 injector
- RareDEF crystals in the connector creating a path to ground
- 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 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.