What it means
The supply line that powers the AdBlue dosing pump is open. Without supply the pump cannot deliver reductant pressure - dosing is suspended and NOx emissions can drift out of compliance.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The reductant pump moves DEF/AdBlue into the exhaust dosing system, and its supply circuit provides the power it needs. The control module detects an open in that pump supply path and sets P05EE when the circuit does not provide the expected electrical connection. Dosing may be suspended, but this code does not prove that every aftertreatment component is unpowered.
Common causes
Most likely first.
- Supply open or relay defective
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
Symptoms
- Check engine light or emissions warning may illuminate
How to diagnose it
- Record freeze-frame data and check for related pump, relay, and aftertreatment codes to determine when the supply fault occurred.
- Inspect the pump supply wiring, fuse and relay connections, and pump connector for damage, corrosion, loose terminals, or a pushed-back pin.
- Check the relevant fuse and relay and verify that the relay receives its expected power and control signals.
- Using the wiring diagram, test continuity through the pump supply path with the circuit safely de-energized, looking for an open between the relay, module, and pump.
- If the external wiring is intact, check the module-side terminals and relay control circuit for a poor connection or internal open.
Common fixes
- Replace a failed fuse or relay after checking for the cause of failure.
- Reseat or repair a pushed-back, loose, or corroded pump supply terminal.
- Repair an open or damaged section of the pump supply harness.
- Repair or replace a confirmed faulty module or internal connection.
Can I keep driving?
You can generally drive if the vehicle has no other warnings or operating problems, but emissions dosing may be disabled and the emissions warning can remain on. Do not ignore a DEF/AdBlue countdown or no-start message, since continued operation can lead to a starting restriction.
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.