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B1973 OBD-II Trouble Code: Passenger Rear Seat Down Switch Circuit Short to Battery

diagnostic check engine light

B1973 code definition

The B1973 trouble code signals a passenger rear seat down switch circuit malfunction.

What the B1973 code means

The B1973 code is a standard OBD-II trouble code that detects an error from the passenger rear seat down switch circuit. This switch is generally located on the outboard side of the passenger seat, and is used to control the vertical movement of the front passenger seat cushion. When pressed, the rear part of the seat cushion will be lowered to adjust the angle of the seat for the passenger. If a circuit error from the passenger rear seat down switch is detected by either the body control module or the powertrain control module (PCM), then the B1973 trouble code is likely to be stored.

What causes the B1973 code?

There are two likely causes of the B1973 trouble code. The first is damaged electrical parts, such as wires, connectors, and fuses. These parts can be in either the passenger rear seat down switch or the power seat system. The second likely cause is a malfunctioning passenger rear seat down switch. While much less common, the code can also be triggered due to a defective body control module.

What are the symptoms of the B1973 code?

When the B1973 trouble code is stored, the front passenger rear seat down switch will likely be inoperable, which means the back of the seat cushion cannot be adjusted down, and likely up as well. It is also fairly common for the check engine soon warning light to come on when this code is detected.

How does a mechanic diagnose the B1973 code?

The B1973 code will be diagnosed using a standard OBD-II trouble code scanner. A reputable technician can use the scanner to view the freeze frame data and assess the code. Additional trouble codes will also be checked for, and if there are multiple codes present, the mechanic will diagnose them in the order that they appear in. The trouble codes should then be reset, the vehicle restarted, and the code checked for. If it is no longer present, then an erroneous trigger or an intermittent error should be assumed.

If the B1973 code is still present, then a thorough visual inspection of the electrical components should be performed. If there are blown fuses, shorted wires, or loose connectors, then they should be replaced. If this inspection yields no results, then a defective passenger rear seat down switch is the likely issue.

Any replacements or repairs should be followed by a resetting of the trouble code, a restart of the vehicle, and another check for the trouble code. Doing this helps the mechanic know as soon as the issue is fully resolved.

Common mistakes when diagnosing the B1973 code

The most common error when diagnosing the B1973 code comes from a failure to abide by the OBD-II diagnosis protocol. The protocol should be observed step by step at all times, as it helps ensure a speedy and accurate diagnosis.

Often electrical component damage is overlooked and passenger rear seat down switches are condemned inaccurately.

How serious is the B1973 code?

The B1973 code does not cause any drivability problems, but it will likely keep the back end of the front passenger seat cushion from being adjusted up or down. This inability to adjust can limit passenger comfort. While not urgent, an inspection should be scheduled when this code is detected.

What repairs can fix the B1973 code?

Possible repairs for the B1973 trouble code are:

Additional comments for consideration regarding the B1973 code

The B1973 code is a manufacturer specific trouble code. Manufacturer specific codes are codes with different definitions for different automakers. The B1973 code suggests a passenger rear seat down switch circuit error for some cars, but detects a different body problem for many other vehicles.

Need help with a B1973 code?

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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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