P2AD8Reductant Pump Motor Position Sensor Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2AD8 reports a reductant pump motor position signal stuck below its valid range. For Hall-type sensors this mostly means the output is pulled to ground permanently: a signal wire shorted to ground, a sensor that has lost its supply, or an internal short in the pump electronics. Without a usable rotor position a brushless pump motor cannot be commutated reliably any more, so the controller may stop the pump to protect it. No manufacturer publishes P2AD8 or a threshold; the general frame is the CARB requirement for circuit checks on emission-relevant inputs. Where the sensor wiring runs inside a sealed pump module, check the external harness, fuses and supply voltage at the pump connector first; if those are sound, the pump unit is the likely replacement.
- What you may notice
- Check engine light and SCR warning
- DEF pump does not run, no dosing
- Likely causes
- LikelyInternal short in the pump electronics
- PossiblePosition signal shorted to ground
- PossibleSensor supply missing, e.g. blown fuse or open feed
- 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: €300 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.