P2AA2
Alternative Fuel Return Line Insufficient Flow
The AFCM detects that the flow through the alternative fuel return line is below the expected minimum for the active operating mode. Restricted line, stuck valve, or pump output too low.
The AFCM detects that the flow through the alternative fuel return line is below the expected minimum for the active operating mode. Restricted line, stuck valve, or pump output too low.
Common causes
- high
Return line restricted by debris
One of the most commonly reported causes for this code — check this first.
Typical part cost: $170-770
- medium
Return line valve stuck closed
A plausible cause — test and verify before replacing parts.
Typical part cost: $170-770
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P2AA2 mean?
P2AA2 means "Alternative Fuel Return Line Insufficient Flow". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P2AA2?
return line restricted by debris; return line valve stuck closed — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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