Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there is a problem with the part of the car that switches between different fuel tanks. Imagine if you had two juice boxes, and the straw that lets you switch between them isn't working.
The P2A99 code indicates an issue with the electrical circuit that controls the valve responsible for selecting the alternative fuel tank. This could mean the circuit is open or not functioning properly.
The P2A99 code is triggered when the Engine Control Module (ECM) detects an open or malfunction in the control circuit for the Alternative Fuel Tank Select Valve C. This valve is responsible for switching between different fuel tanks in vehicles that can use alternative fuels.
• Check Engine Light is on
• Inability to switch fuel tanks
• Possible fuel system performance issues
• Faulty Alternative Fuel Tank Select Valve
• Open or shorted wiring in the valve circuit
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for the valve.
• Test the valve for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the faulty Alternative Fuel Tank Select Valve.
• Reprogram or replace the ECM if necessary.
• OBD-II Scanner
• Multimeter
• Screwdriver set
$150 - $500
Moderate
• Chevrolet Volt
• Toyota Prius
• Ford Fusion Hybrid
• Regular maintenance checks on the fuel system.
• Ensure proper installation of alternative fuel components.
• Keep the vehicle's software updated.
Circuit Issue
• Do not ignore the check engine light.
• Consult with a professional mechanic if unsure.
• Regularly inspect the vehicle's fuel system.
Check with the vehicle manufacturer for warranty coverage on fuel system components.
This code is more common in vehicles that have been modified to use alternative fuels.
Moderate – It should be addressed soon to avoid further fuel system issues.
Ignoring this code may lead to fuel system malfunctions, which can affect vehicle safety and emissions compliance.
• Engine running
• Alternative fuel system engaged
The Alternative Fuel Tank Select Valve is typically located near the fuel tanks, often accessible from underneath the vehicle.
Q: Can I drive with a P2A99 code?
A: It's possible to drive short distances, but it's best to get it checked soon to avoid fuel system issues.
Q: Will this code affect my fuel economy?
A: Yes, if the fuel tank selection is not working properly, it could lead to inefficient fuel usage.
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