U0666
Lost Communication With Reductant Pressure Sensor
U0666 is an OBD-II diagnostic trouble code meaning: Lost Communication With Reductant Pressure Sensor. Common causes: open or short circuit in the sensor circuit, reagent pressure sensor malfunction. Estimated repair cost: $56–167.
Symptoms
- Check Engine Light Is On
- Reduced engine power
- SCR system malfunction message appears
- Increased reagent consumption
- Increased NOx emissions
Causes
- Open or short circuit in the sensor circuit
- Reagent pressure sensor malfunction
- Connector problems or contact corrosion
- SCR ECU malfunction
- Problems with power or grounding of the sensor
How to Fix
- Check the integrity of the sensor wiring and connectors
- Check the power supply and grounding of the sensor
- Test the reagent pressure sensor
- Check the SCR ECU for errors
- Replace reagent pressure sensor if necessary
Related codes
Error U0666 by Vehicle Brand
FAQ
What does the U0666 code mean?
U0666 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Reductant Pressure Sensor
What causes a U0666 error code?
The most common causes of U0666 include: Open or short circuit in the sensor circuit; Reagent pressure sensor malfunction; Connector problems or contact corrosion; SCR ECU malfunction.
How do I fix a U0666 diagnostic trouble code?
To fix U0666: Check the integrity of the sensor wiring and connectors. Check the power supply and grounding of the sensor. Test the reagent pressure sensor. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U0666?
Yes, but get it checked soon
How much does it cost to fix U0666?
The estimated repair cost for U0666 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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