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 getting a signal that the pressure in the second fuel tank (which uses a different kind of fuel, like natural gas) is too low. It's like when a balloon doesn't have enough air in it.
The P2A43 code indicates a problem with the electrical circuit that monitors the pressure in the alternative fuel tank B. The signal from the pressure sensor is lower than expected, suggesting a possible issue with the sensor or its wiring.
The engine control module (ECM) monitors the pressure in the alternative fuel tank B via a pressure sensor. If the sensor's circuit voltage is lower than the specified range, the ECM triggers the P2A43 code. This could be due to a faulty sensor, wiring issues, or a problem with the ECM itself.
• Check Engine Light is on
• Poor fuel efficiency
• Possible fuel odor
• Faulty pressure sensor
• Damaged wiring or connectors
• Faulty ECM
ECM: Engine Control Module
CNG: Compressed Natural Gas
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the pressure sensor for proper operation.
• Replace the faulty pressure sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$150 - $400
Moderate
• Chevrolet Volt
• Toyota Prius (CNG models)
• Honda Civic GX
• Regularly inspect fuel system components.
• Ensure proper maintenance of electrical connections.
• Use quality fuel to prevent sensor contamination.
Sensor Issue
• Do not ignore the Check Engine Light.
• Get the vehicle inspected by a professional.
• Avoid using the vehicle if you smell fuel.
Check if your vehicle's warranty covers sensor replacements.
This code is more common in vehicles using alternative fuels like CNG or LPG, where pressure sensors are critical for fuel management.
Moderate – It's important to address this issue to ensure proper fuel management and prevent potential safety hazards.
Driving with a fuel system issue can be dangerous. Ensure repairs are conducted by a qualified technician.
• Vehicle at operating temperature
• Engine running and fuel system pressurized
The pressure sensor for alternative fuel tank B is typically located near the tank itself, often underneath the vehicle.
Q: Can I drive with a P2A43 code?
A: It's not recommended to drive with this code as it could lead to inefficient fuel use and potential safety hazards.
Q: How can I reset the P2A43 code?
A: You can reset the code using an OBD-II scanner, but it's important to fix the underlying issue first.
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.