The P20A6: Reductant Injection Air Pressure Control Valve Circuit/Open fault code indicates an issue where the circuit responsible for the reductant injection air pressure control valve is open. This valve controls air pressure in the reductant injection system, which ensures proper delivery of diesel exhaust fluid (DEF) into the exhaust system. An open circuit can disrupt the valve’s operation, leading to emissions system issues. The problem could be caused by an open circuit, a faulty valve, or a malfunctioning control module.
P20A6 – Quick Overview
Code | Information |
---|---|
Meaning | P20A6: Reductant Injection Air Pressure Control Valve Circuit/Open |
Is it serious? | Yes, it can lead to improper DEF delivery, which can cause higher emissions and potentially trigger warning lights. |
Possible causes | – Open circuit in the reductant injection air pressure control valve wiring – Faulty control valve – Faulty control module |
How to diagnose? | – Inspect the wiring for open circuits – Test the reductant injection air pressure control valve – Check the control module functionality |
P20A6 Meaning
The P20A6 code indicates that there is an open circuit in the wiring controlling the reductant injection air pressure control valve. This valve plays a key role in managing the air pressure necessary for proper DEF injection into the exhaust system. When this circuit is open, the valve may not function correctly, leading to inefficient DEF dosing and increased emissions.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for any related fault codes that could provide further insight into the issue with the reductant system. | OBD-II Scanner |
Inspect Wiring for Open Circuits | Visually inspect the wiring connected to the reductant injection air pressure control valve for any signs of breaks, disconnections, or damage. | Flashlight, Multimeter |
Test the Reductant Injection Air Pressure Control Valve | Use a diagnostic tool to test the valve to ensure it is functioning correctly and within manufacturer specifications. Replace if necessary. | Multimeter, Diagnostic Tool |
Check the Control Module Functionality | Test the control module responsible for managing the valve to ensure it is sending the proper signals to operate the valve. | Diagnostic Tool |
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 confirm the issue has been resolved. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | Re-scan the vehicle after the test drive to ensure the P20A6 code does not return. If the code reappears, further diagnostics may be needed. | OBD-II Scanner |

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