What it means
The ECM detects a generic fault on the reductant pump motor position sensor circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
The reductant pump motor moves AdBlue/DEF through the emissions-treatment system, and its position sensor reports the motor's position to the engine control module. P2AD6 sets when the module detects a general fault in that sensor circuit and cannot rely on the position reading for pump control.
Common causes
Most likely first.
- Reductant pump motor position sensor fault
- Wiring or connector fault
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
How to diagnose it
- Read freeze-frame data and scan for related reductant-system faults, then check live pump position data for a missing or implausible reading.
- Inspect the reductant pump position-sensor connector and harness for corrosion, fluid intrusion, loose terminals, or damage.
- Check the sensor's power, ground, and signal circuits for continuity, shorts, and poor connections using the wiring diagram and manufacturer's specification.
- If the circuits are sound, test the pump motor position sensor and compare its output with the manufacturer's specification.
- After repair, clear the faults and verify that pump position data responds correctly and the reductant system completes its check.
Common fixes
- Clean and secure the position-sensor connector and repair damaged wiring.
- Restore a failed sensor power or ground connection.
- Replace the reductant pump motor position sensor if its output fails the manufacturer's specification.
- Replace the pump assembly only if the sensor is not separately serviceable or the assembly itself fails testing.
Can I keep driving?
The vehicle may remain driveable initially, but emissions control can be impaired and an AdBlue/DEF warning may progress to a restart restriction countdown. Check the warning message and arrange repair promptly; do not ignore any displayed countdown.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.