The P20A5: Reductant Purge Control Valve Stuck Closed fault code refers to an issue where the reductant purge control valve is stuck in the closed position. This valve is crucial in controlling the flow of diesel exhaust fluid (DEF) within the emissions system. When the valve is stuck closed, it can block the proper flow of DEF, preventing efficient emissions control. Common causes include a sticking valve, a faulty valve actuator, or blockages in the purge lines.
P20A5 – Quick Overview
Code | Information |
---|---|
Meaning | P20A5: Reductant Purge Control Valve Stuck Closed |
Is it serious? | Yes, it can cause improper emissions control and lead to increased emissions, potentially triggering warning lights. |
Possible causes | – Sticking or jammed reductant purge control valve – Faulty valve actuator – Blocked purge lines |
How to diagnose? | – Inspect the reductant purge control valve for sticking or jamming – Test the valve actuator – Check for blockages in the purge lines |
P20A5 Meaning
The P20A5 code indicates that the reductant purge control valve is stuck in the closed position, preventing the proper flow of DEF through the emissions system. This valve helps manage the dosing of DEF into the exhaust system to reduce harmful emissions. If it is stuck closed, the system may be unable to purge or flow DEF, leading to poor emissions control and potential damage to the system.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for additional fault codes related to the emissions system, which may provide further information. | OBD-II Scanner |
Inspect the Purge Valve for Sticking or Jamming | Visually inspect the reductant purge control valve for signs of sticking or jamming that could prevent it from opening properly. | Flashlight, Safety Gloves |
Test the Valve Actuator | Use a diagnostic tool to test the valve actuator and ensure it is functioning correctly and not causing the valve to remain closed. | Multimeter, Diagnostic Tool |
Check for Blockages in Purge Lines | Inspect the DEF purge lines for blockages, including crystallization or debris, that could prevent proper flow through the valve. | Flashlight, Inspection Mirror |
Clear the Code and Test Drive | After completing repairs, clear the fault code using an OBD-II scanner and take the vehicle for a test drive to verify the issue is resolved. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | Re-scan the vehicle after the test drive to ensure the P20A5 code does not return. If the code reappears, further diagnostics may be necessary. | OBD-II Scanner |

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