What is OBD-II Code P2A62 – Alternative Fuel Tank B Level Sensor Circuit High


As a mechanic, one of the most important diagnostic tools I use is the On-Board Diagnostics (OBD) system. OBD-II Code P2A62 – Alternative Fuel Tank B Level Sensor Circuit High is a common OBD-II trouble code that communicates a problem with the fuel system.

In this article, I will explain what OBD-II Code P2A62 is, what causes it, how to diagnose and repair it as a mechanic, and how car owners can identify and address the issue.

What is OBD-II Code P2A62?

OBD-II Code P2A62 is a trouble code that indicates a high voltage reading in the Alternative Fuel Tank B Level Sensor Circuit. This sensor is responsible for detecting the level of fuel in the alternative fuel tank, typically in hybrid or electric vehicles.

When the fuel tank level sensor circuit detects an unusually high voltage, it turns on the Check Engine Light (CEL) and logs a code in the vehicle’s onboard computer. This code is recorded in the OBD-II system and can be retrieved using a diagnostic scanner by a mechanic.

What causes P2A62 code?

There are many potential causes for the Alternative Fuel Tank B Level Sensor Circuit High trouble code. Some of the common causes can include:

1. Faulty fuel tank level sensor – This is the most common cause of P2A62 trouble code.

2. Corrosion or damage to the sensor connector – This can cause a poor connection and result in a high voltage reading.

3. Circuit issues in the wiring – This can be caused by worn wires or moisture in the wiring.

4. Issues in the hybrid or electric system – A malfunction in the hybrid or electric system can also be a contributing factor.

How to diagnose P2A62 code

Diagnosing OBD-II Code P2A62 requires understanding of the fuel system. As a mechanic, here are the diagnostic steps I would take:

Step 1: Inspect the wiring and connectors – Before replacing any components, I would inspect the wires and connectors for any damage or corrosion.

Step 2: Check the fuel tank level sensor – I would use a multimeter to check the resistance of the fuel level sensor. If the resistance did not match the manufacturer’s specifications, I would replace the sensor.

Step 3: Check the alternative fuel tank – I would inspect the alternative fuel tank to ensure it is working properly. If there were any issues, I would replace or repair it.

Step 4: Check the hybrid or electric system – Finally, I would check the hybrid or electric system to ensure it is functioning properly. If any faults are found, I would repair them accordingly.

How to fix P2A62 code

Once the fault has been identified and diagnosed, it can be repaired. The appropriate solution will depend on what caused the high voltage reading.

Here are some general repair steps for P2A62:

Step 1: Replace the fuel tank level sensor – If the sensor is found to be faulty, it should be replaced with a new one.

Step 2: Repair or replace damaged wiring – If the wiring or connectors are damaged or corroded, they should be repaired or replaced as necessary.

Step 3: Repair or replace the alternative fuel tank – If there is a fault with the alternative fuel tank, it should be repaired or replaced.

Step 4: Repair any hybrid or electric system issues – If the trouble code is due to a hybrid or electric system issue, that issue should be addressed and repaired accordingly.

Frequently Asked Questions

Q1. What should I do if my Check Engine Light turns on?

A. If your Check Engine Light turns on, it is important to take your vehicle to a mechanic for diagnostic testing. Ignoring the CEL can lead to additional problems and costly repairs down the line.

Q2. Can I continue driving my car with P2A62 code?

A. It is not recommended to continue driving your vehicle with the P2A62 trouble code, as it could lead to further damage and expensive repairs.

Q3. How often should I have my car’s OBD system checked?

A. It is recommended to have your car’s OBD system checked at least once a year, or any time the CEL turns on.

Q4. Are there any steps I can take to prevent P2A62 trouble code from occurring?

A. To prevent P2A62 from occurring, it is important to perform regular maintenance and follow the manufacturer’s recommended service schedule. Additionally, avoiding rough driving and maintaining the fuel level can help prevent issues with the fuel system.

Q5. How much does it cost to repair P2A62 trouble code?

A. The cost of repairing P2A62 will depend on the cause of the trouble code, as well as the make and model of your vehicle. In general, repairs can range from a few hundred to a few thousand dollars.


OBD-II Code P2A62 is a common trouble code that is related to the fuel system. As a mechanic, it is important to understand the causes and diagnostic steps necessary to identify and repair the issue. Car owners can identify and address the issue by staying vigilant and following the recommended service schedule. With proper maintenance and care, your vehicle’s OBD system can help ensure reliable and trouble-free performance.

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