B1981 OBD-II Trouble Code: Memory Off Switch Circuit Short to Battery

B1981 code definition

The B1981 trouble code detects a memory off switch circuit error.

What the B1981 code means

The B1981 code is a standard OBD-II trouble code that detects a circuit malfunction from the memory off switch. The memory system allows your vehicle to remember certain settings, such as the seat and steering wheel position, so that you don’t have to make adjustments when you enter the vehicle after the settings have been changed. If a memory off switch circuit error is detected by the body control module or the powertrain control module (PCM), then the B1981 trouble code may be triggered.

What causes the B1981 code?

The B1981 trouble code is almost always the result of damaged electrical components in the memory system, such as shorted wires, open or corroded connectors, or blown fuses. The code can also be caused by a failed memory switch, or a defective body control module.

What are the symptoms of the B1981 code?

When the B1981 trouble code is detected, the memory settings will likely all be reset. There will be no way to access the memory settings, and all of the components will need to be manually adjusted. It is also possible that the check engine soon warning light will illuminate on the vehicle’s gauge cluster.

How does a mechanic diagnose the B1981 code?

The B1981 code will be diagnosed using a standard OBD-II trouble code scanner. A trained mechanic will use the scanner to view the freeze frame data and assess the code, while also checking for the presence of additional trouble codes. If multiple codes are detected, then the mechanic will diagnose them in the order that the scanner displays them in. The trouble codes will then be reset and the vehicle restarted, so the B1981 code can be checked for. If the code is no longer detected, then it was likely caused by an intermittent problem, or was inaccurately detected.

If the code remains present, then the mechanic should perform a thorough visual inspection of the electrical components in the system. Next, the memory switch and body control module should be checked.

Any time a part is replaced or repaired, the trouble codes should again be reset, the vehicle again restarted, and the code searched for. By doing this, the technician will know as soon as the issue is resolved, so that erroneous repairs are not made.

Common mistakes when diagnosing the B1981 code

The most commonly made mistake when diagnosing this code comes from a failure to observe the OBD-II trouble code diagnosis protocol. It is imperative that mechanics always adhere to the protocol, to help guarantee efficient and accurate diagnoses and repairs.

Body control modules are sometimes inaccurately condemned because damaged electrical components were not noticed. This is a costly mistake that not only costs excess time and money, but won’t fix the problem.

How serious is the B1981 code?

The B1981 trouble code will not keep a car from being drivable, or result in drivability concerns. However, it can limit the practicality and comfort of the vehicle, so an inspection should be scheduled when the code is noticed.

What repairs can fix the B1981 code?

Repairs for the B1981 trouble code include:

• Replacement of wires, connectors, and fuses
• Replacement of the memory switch
• Replacement of the body control module

Additional comments for consideration regarding the B1981 code

The B1981 trouble code is a manufacturer specific code, which means that the definition varies depending on the automaker. This code can detect a memory off switch circuit error in some cars, but it may signal a different body problem in other vehicles. As with all codes, the mechanic should be aware of the vehicle that is being worked on when diagnosing the B1981 trouble code.

Need help with a B1981 code?

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