How to Troubleshoot a Body Control Module

by Jennifer Garcia

Body control modules can be troublesome devices, especially when they make your vehicle do strange things as a result of the BCM malfunctioning. A BCM is defined as a computer component in a vehicle that operates, regulates and checks the vehicle's electronic devices. When vehicles first began coming equipped with electronic devices, there existed a separate module for every device.

Pay attention to your vehicle. When a BCM is malfunctioning, the electronic components of the vehicle will begin acting in strange ways and not working properly. Some of the possible causes of a malfunctioning BCM include the clock on the radio not keeping its time and reverting to 12:00 when the vehicle is turned off, then turned on again.

Check to make sure all the electronic devices are working properly. If you use a key fob to lock and unlock the doors, the function may not work. Or if the doors do lock and unlock properly, other things can happen in conjunction with the lock/unlock action, such as the horn honking or the lights blinking each time you use the fob.

Turn the radio and CD player on. Sometimes a CD player will stop playing a CD and will begin broadcasting a radio station. The frequency of these actions depends on the severity of the malfunctioning BCM.

Check the fuse box if you suspect that your vehicle's BCM is on the blink. Make sure all the fuses are in good shape. If any are burnt out, replace them immediately. If you have replaced blown fuses and you are still experiencing problems with your vehicle, take it to the dealer so the mechanics there can run a diagnostics test on the vehicle.

Take your vehicle to Auto Zone or Checker or another similar auto parts store. They also have the capabilities to run a diagnostic test on your vehicle if you are short on time or can't take it in to the dealer. The only drawback to taking it to an auto parts store is that, most of the time, the person performing the diagnostic test can't read the code and will refer you to a dealer, anyway.

Tip

  • check Taking your car to the dealer or other certified mechanic is always your best bet.

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