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Faulty Body Control Module

Learn the Symptoms of a Bad Body Control Module

Today we’re going to learn symptoms of a bad body control module.
The purpose of the body control module is to control the electrical accessory system.
It controls the anti-theft system, instrument cluster, windows and more.
The location of the body control module varies between cars.
It could be on the driver’s side to the left of the brake pedal, behind the dashboard, or under the center console.

Symptoms

When it comes to the symptoms, it really depends on how your BCM got affected.
Maybe a specific circuit inside the body control module is corroded and only allows certain accessories to work. Or there was a complete failure resulting in no accessories working at all.
Today i will be giving you some symptoms that could potentially happen with your car.

1

The first symptom of a bad body control module is having your check engine light on.
Now you could have multiple codes that have to do with the BCM and the circuits it controls, but the most common code that I’ve seen when the BCM goes bad is the u0140 code.
Which basically means there’s no communication to the BCM.
Make sure there’s no turned wires or corroded connectors as these can also cause the code to appear.

2

The second symptom is the accessories not working as they should.
The non-working accessories can vary from car to car but let me give you some examples that can happen.
For instance, you turn your high beams on and your windows roll down, or you turn on your left turning signal and the car honks as well.
Basically since the body control module is not working properly, any electrical accessory in your vehicle can act strangely and dysfunctional.

3

The third symptom of a bad body control module is only certain accessories working.
Again this can vary from car to car, but for example your wipers, locks, and windows may not work while all other accessories in your car work just fine.

4

The fourth symptom that can happen is a no crank no start.
If the body control module is faulty, it can lose communication with the ECM, and as a result it will prevent your car from starting.
Now before assuming you have a bad BCM, make sure to check for blown fuses, torn wires, and corrosion.
Sometimes water can get in between the connectors and the pins, causing corrosion.
If you’re lucky you can get your BCM working again by cleaning it.

Check out the following products.

Computer Modules

Electrical Switches and Components

Electrical Switch Panels and Components

Fuse Boxes

Here is an article on Braided Hose Assembly with AN Fittings. You might also like this post on High Pressure Mechanical Fuel Pumps – How They Work. And then there is this post on Electric Fuel Pumps – How They Work. We also have a YouTube channel for you to take a look at. @uzbasicmotorsports.