B1326 OBD-II Trouble Code: Door Ajar Lamp Circuit Short to Ground

diagnostic check engine light

B1326 code definition

The B1326 trouble code detects a circuit error with the door ajar lamp.

What the B1326 code means

The B1326 code is a standard OBD-II trouble code that notes an issue with the door ajar lamp circuit. The door ajar lamp illuminates when one of the vehicle’s doors is not properly latched. If the door ajar lamp is not operating correctly, then the B1326 trouble code will be stored.

What causes the B1326 code?

Potential causes of the B1326 trouble code are:

What are the symptoms of the B1326 code?

When the B1326 trouble code is detected, the door ajar Warning Light will likely stay illuminated at all times, even when all of the doors are properly closed. The light may also stay on when the vehicle is turned off, which in many cars means the interior lights will stay on. This can result in the battery dying if the car remains turned off for more than a few hours, and then the vehicle will not be able to start.

How does a mechanic diagnose the B1326 code?

The B1326 code will likely be diagnosed using a standard OBD-II trouble code scanner. A scanner is not always necessary to detect this issue, since it will be apparent with the door ajar Warning Light staying illuminated, but it’s still a good idea to use a scanner for a preliminary diagnosis, as it can help the mechanic identify the exact code, and check for the presence of additional trouble codes. If there are multiple codes present, then the technician should inspect them in the order in which the scanner displays them. The trouble codes will then be reset, the vehicle restarted, and the code again checked for.

If the problem and the code remain, the mechanic should begin by visually inspecting the electrical components in the system, and replacing any wires, fuses, or connectors that are damaged. The circuit to ground voltage should then be tested. If the problem remains, the door latches for each door will need to be lubricated, and the door ajar Warning Light dimmer tested for the proper adjustment. If none of these inspections yields results, then one of the door ajar switches is broken.

After any components are replaced or repaired, the mechanic should again reset the trouble codes, or test the door ajar Warning Light. This will help the technician know as soon as the problem has been fixed.

Common mistakes when diagnosing the B1326 code

The most frequently made error when diagnosing the B1326 code comes from a failure to properly follow the OBD-II code diagnosis protocol. Mechanics should always follow the protocol step by step, as it helps guarantee diagnoses that are efficient, and repairs that are accurate.

It is fairly common for fully functional door ajar switches to be improperly replaced because an electrical error was overlooked.

How serious is the B1326 code?

The B1326 trouble code may keep a car from being drivable. If the door ajar Warning Light staying on triggers the interior lamps to stay on, then the vehicle’s battery may die with regularity. Because of this, the vehicle should be inspected as soon as the B1326 code is detected.

What repairs can fix the B1326 code?

Repairs for the B1326 trouble code include:

  • Door ajar switch replacement
  • Replacement of electrical components in the system, including the circuit
  • Door latch service or replacement
  • Adjustment of the door ajar Warning Light dimmer

Additional comments for consideration regarding the B1326 code

The B1326 trouble code detects a door ajar lamp circuit issue in many vehicles, but in some makes and models this code represents a different error.

Need help with a B1326 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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