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B1310 OBD-II Trouble Code: Power Door Unlock Circuit Failure

diagnostic check engine light

B1310 code definition

The B1310 trouble code notes a malfunction with the power door unlock circuit.

What the B1310 code means

The B1310 code is a generic OBD-II trouble code that detects a circuit malfunction with the power door unlock system. Vehicles have one door unlock system that controls all of the door locks, as well as the trunk lock, so the B1310 code applies to all of the vehicle’s locks. If the powertrain control module (PCM) or body control module notes an issue with the power door unlock circuit, then the B1310 code may be detected.

What causes the B1310 code?

The most likely causes for the B1310 trouble code are:

What are the symptoms of the B1310 code?

The B1310 trouble code will likely result in a defective power door lock system. The power door lock and unlock features may not work, or they may only work intermittently.

How does a mechanic diagnose the B1310 code?

The B1310 code should be diagnosed using a standard OBD-II trouble code scanner. A reputable mechanic can look at the freeze frame data to assess the code, and to check for other trouble codes that may be present. If the technician notes that there are multiple codes detected, then they will need to be diagnosed in the order in which the scanner displays them. The technician may then reset the trouble codes, restart the vehicle, and check to see if the code is still present, though this may be unnecessary if the issue has already been confirmed. If the power door lock system appears to be working normally, and the B1310 code is no longer detected after the reset, then an erroneous trigger or an intermittent error are likely to blame.

The mechanic should begin by visually inspecting the power door lock system’s electrical components. Any blown fuses, short wires, or open or corroded connectors will need to be replaced. Next, the power door lock actuator and relay will require inspection. The mechanic can perform this inspection visually, or possibly by pressing the power door lock or unlock button and listening to the sound that is made.

Any time the mechanic repairs or replaces a component, the trouble codes will need to be reset, the vehicle will need to be restarted, and the B1310 code will be checked for. By doing this, the technician will know if the power door unlock circuit issue has been fixed.

Common mistakes when diagnosing the B1310 code

The most common error that is made when diagnosing the B1310 trouble code comes from not following the OD-II diagnosis protocol. Technicians should always abide by the protocol exactly, as it helps ensure an accurate and efficient diagnosis and repair.

It is fairly common for fully functional power door lock relays and actuators to be unnecessarily replaced when the only problem is an electrical error.

How serious is the B1310 code?

A vehicle with a detected B1310 code will likely experience issues in the power door lock system, either with locking the doors and trunk, unlocking them, or both. As the power door lock system is a crucial security feature, an inspection should be scheduled as soon as the code is noticed.

What repairs can fix the B1310 code?

Potential repairs for the B1310 trouble code are:

Additional comments for consideration regarding the B1310 code

Even though the B1310 trouble code usually notes a power door unlock circuit failure, the code can have an alternate definition depending on the make and model of the vehicle. Before any repairs are made, the mechanic should verify that the B1310 code signals a power door unlock circuit issue for the vehicle that is being inspected.

Need help with a B1310 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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