P05EE: Reductant Pump Supply Voltage Circuit/Open

The electric supply pump in the diesel exhaust fluid (DEF, AdBlue) tank module builds the dosing pressure for the SCR catalyst. Its supply voltage is monitored separately from the pump control circuit (P208A ff); CARB requires SCR components and their outputs to be checked for circuit faults and function. P05EE means the supply circuit is open: when the supply is switched on, no voltage or current reaches the pump branch. Ford's comparable check flags a pump controller voltage below 6 V. Chrysler (FCA) lists this code among those that trigger the DEF inducement: a 'Service DEF System' warning, a countdown after 50 miles and no restart after 150 miles (P241D). Without supply the pump cannot build pressure, dosing stops and NOx rises; pressure or SCR efficiency codes may follow.

Symptoms

• Check engine light on
• DEF/AdBlue warning, possibly countdown to no-restart
• Follow-up codes for low DEF pressure or SCR efficiency

Most likely causes

• Connector at the pump or tank module corroded or loose
• Open wire in the harness to the tank
• Fuse or relay of the pump supply faulty
• Pump or tank module open internally

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the AdBlue/DEF level and quality, and do not add additives or water
2. Check the continuity of the wire between the component and the control module.
3. Look for white crystals around the injector and the tank
4. Check connectors and heaters with the scanner
5. Run the dosing test available on your diagnostic tool
6. Replace parts only when the test points to that component

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P05EE means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 5: Speed and idle
• EE: Specific fault in that system

Frequently asked questions

Can I keep driving with code P05EE?

Deal with it soon. If the instrument cluster shows a countdown, the car may not restart once it reaches zero.

What causes code P05EE?

The most common causes are: connector at the pump or tank module corroded or loose; open wire in the harness to the tank; fuse or relay of the pump supply faulty.

Related codes

• P208AReductant Pump A Control Circuit/Open
• P208CReductant Pump A Control Circuit Low
• P208DReductant Pump A Control Circuit High
• P20E8Reductant Pressure Too Low
• P21CBReductant Control Module Supply Voltage Low
• P21CCReductant Control Module Supply Voltage High

Sources

• law.cornell.edu: 13 CCR 1968.2
• static.nhtsa.gov: MC 10184705 9999
• gsi.ext.gm.com: 14OBDG10 Engine Diagnostics
• fordservicecontent.com: obd summary diesel 2023

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.