Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble controlling a valve that switches between different fuel tanks. It's like a switch that isn't working properly.
The P2A97 code indicates a problem with the electrical circuit that controls the valve responsible for selecting between alternative fuel tanks. This could mean the circuit is not getting enough power or is interrupted.
The P2A97 code is triggered when the Engine Control Module (ECM) detects a low voltage condition in the control circuit of the Alternative Fuel Tank Select Valve B. This valve is part of the fuel system that allows the vehicle to switch between different fuel sources, such as gasoline and compressed natural gas (CNG). A low circuit condition means the ECM is not receiving the expected voltage signal from the valve's control circuit.
• Check Engine Light is on
• Difficulty in switching between fuel tanks
• Possible fuel odor if there's a leak
• Faulty Alternative Fuel Tank Select Valve B
• Open or short circuit in the valve's wiring
• Faulty ECM or control module
ECM: Engine Control Module
CNG: Compressed Natural Gas
• Use an OBD-II scanner to verify the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the voltage and continuity in the valve's circuit.
• Repair or replace damaged wiring or connectors.
• Replace the Alternative Fuel Tank Select Valve B if faulty.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Chevrolet Volt
• Toyota Prius
• Honda Civic Natural Gas
• Regularly inspect and maintain the fuel system.
• Ensure connectors and wiring are secure and free from corrosion.
• Use the correct type of fuel for your vehicle.
Sensor Issue
• Avoid switching fuel types until the issue is resolved.
• Consult a professional mechanic for diagnosis and repair.
Check your vehicle's warranty for coverage on fuel system components.
This code is more common in vehicles that use alternative fuels, such as hybrids or CNG vehicles.
Moderate – It should be addressed soon to ensure proper fuel system function.
Ignoring this code may lead to fuel system malfunctions, which can be hazardous.
• Engine running
• Attempt to switch fuel tanks
The Alternative Fuel Tank Select Valve B is typically located near the fuel tanks or along the fuel line.
Q: Can I drive my car with this code?
A: It's possible to drive, but you may experience issues with fuel switching. It's best to get it checked soon.
Q: Will this code cause my car to fail emissions tests?
A: It might, as it involves the fuel system, which is part of emissions control.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.