P2063: Reductant/Regeneration Supply Control Circuit Low

Definition

The OBD2 code P2063 indicates a low voltage or malfunction in the reductant (urea) supply control circuit, which is part of the diesel exhaust fluid (DEF) system used for emissions control

Common causes

Faulty reductant pump
Damaged wiring or connectors
Low reductant fluid level
Failed reductant level sensor
Short circuit in the control circuit
Faulty engine control module (ECM)
Blocked or restricted reductant supply line

Common misdiagnoses

Faulty fuel injectors
Defective fuel pump
Clogged fuel filter
Bad mass air flow sensor
Malfunctioning oxygen sensors
Exhaust system leaks
Faulty engine control module (ECM)
Wiring issues or shorts in the circuit
Defective reductant pump
Low DEF (diesel exhaust fluid) levels

Troubleshooting steps

1. Check for Additional Codes

Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are multiple issues
2. Inspect the Wiring and Connectors
3. Visually inspect the wiring and connectors associated with the reductant supply control circuit. Look for signs of damage, corrosion, or loose connections
4. Pay special attention to the wiring harness leading to the DEF injector and the DEF tank
5. Test the Reductant Control Module
6. If your vehicle is equipped with a reductant control module, check its functionality. This may involve testing the module for proper voltage and ground signals
7. Consult the vehicle’s service manual for specific testing procedures
8. Check the DEF Level
9. Ensure that the DEF tank is filled to the appropriate level. Low DEF levels can trigger this code
10. If the DEF is contaminated or of poor quality, it may also cause issues
11. Inspect the DEF Pump
12. Test the DEF pump for proper operation. Ensure it is delivering the correct amount of fluid to the injector
13. Check for any blockages in the DEF lines that could prevent fluid flow
14. Examine the DEF Injector
15. Inspect the DEF injector for clogs or malfunctions. A faulty injector may not deliver the required amount of DEF into the exhaust stream
16. Clean or replace the injector if necessary
17. Check for Leaks
18. Look for any leaks in the DEF system, including the tank, lines, and injector. Leaks can lead to low pressure and trigger the code
19. Perform a System Reset
20. After addressing any issues, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns
21. Consult Technical Service Bulletins (TSBs)
22. Check for any TSBs related to the P2063 code for your specific vehicle make and model. Manufacturers may have issued updates or fixes for known issues
23. Seek Professional Help
24. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis and repair. By following these troubleshooting steps, you can identify and resolve the underlying issue causing the P2063 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Additional Codes

2. Inspect the Wiring and Connectors

3. Visually inspect the wiring and connectors associated with the reductant supply control circuit. Look for signs of damage, corrosion, or loose connections

4. Pay special attention to the wiring harness leading to the DEF injector and the DEF tank

5. Test the Reductant Control Module

6. If your vehicle is equipped with a reductant control module, check its functionality. This may involve testing the module for proper voltage and ground signals

7. Consult the vehicle’s service manual for specific testing procedures

8. Check the DEF Level

9. Ensure that the DEF tank is filled to the appropriate level. Low DEF levels can trigger this code

10. If the DEF is contaminated or of poor quality, it may also cause issues

11. Inspect the DEF Pump

12. Test the DEF pump for proper operation. Ensure it is delivering the correct amount of fluid to the injector

13. Check for any blockages in the DEF lines that could prevent fluid flow

14. Examine the DEF Injector

15. Inspect the DEF injector for clogs or malfunctions. A faulty injector may not deliver the required amount of DEF into the exhaust stream

16. Clean or replace the injector if necessary

17. Check for Leaks

18. Look for any leaks in the DEF system, including the tank, lines, and injector. Leaks can lead to low pressure and trigger the code

19. Perform a System Reset

20. After addressing any issues, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

21. Consult Technical Service Bulletins (TSBs)

22. Check for any TSBs related to the P2063 code for your specific vehicle make and model. Manufacturers may have issued updates or fixes for known issues

23. Seek Professional Help

24. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis and repair. By following these troubleshooting steps, you can identify and resolve the underlying issue causing the P2063 code