Bypassing the BCM...
Thread Starter
Le Mans Master
Joined: Jun 2002
Posts: 8,352
Likes: 102
From: In the pit, trying to love someone.
Bypassing the BCM...
Is it possible? Plenty of other cars work just fine without one. Why can't a Corvette be rewired to work without it? Do we really need a computer to control the door locks and how a window goes up and down?
Tech Contributor
Joined: Jan 2007
Posts: 19,353
Likes: 1,125
From: Dyer, IN
Of course it's possible, at significant expense.....and extra weight...given you want all the same functionality.
Thread Starter
Le Mans Master
Joined: Jun 2002
Posts: 8,352
Likes: 102
From: In the pit, trying to love someone.
Windows should be simple, same as the door locks, radio, and hvac, provided you don't have dual zone climate control. I can see the DIC not functioning, but most of that can be handled by the gauges, which could be wired to run directly off the sensors like in other cars.
I could see losing the DIC, TPM, and some of the other dash functions like MPG, the trip odometers, etc.
The more I sit here and actually think about it, the more I've decided it is a bad idea for most owners
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
You must consider that the PCM and BCM have security within as well as all the functions the BCM handles such as wipers, lights, memory and tons of things. Sort of look at it like, the PCM will have to come out, which means the TCS, TAC and so on, none will work. You would need a new setup to run the engine, cable from a new gas pedal to the butterfly valve with at the moment is electronically controlled. All windows and doors would need manual controls or new switches/rewiring and so on.
The car was designed or lets say, pre-designed, with these controls in place. They then design the systems to work together. Trying to go backwards would be s serious problem. Not saying you can't remove the intake and put a carb on it, not sure if there's a place for a distributor or not but that would be an issue...rewire the starter/solenoid directly to the ignition, same for the fuel pump. Lights would all have to be rewired manually to switches you would have to add. Its possible but frankly, its not worth it. By the time you are done, the car will get less MPG and be near worthless in value, so you'll never be able to sell it.
The car was designed or lets say, pre-designed, with these controls in place. They then design the systems to work together. Trying to go backwards would be s serious problem. Not saying you can't remove the intake and put a carb on it, not sure if there's a place for a distributor or not but that would be an issue...rewire the starter/solenoid directly to the ignition, same for the fuel pump. Lights would all have to be rewired manually to switches you would have to add. Its possible but frankly, its not worth it. By the time you are done, the car will get less MPG and be near worthless in value, so you'll never be able to sell it.
Racer
Joined: Mar 2011
Posts: 377
Likes: 3
From: Cudahy WI
Why would you want to? In a car with a properly functioning BCM, it makes your life a lot easier. Easier to diagnose, simpler wiring for advanced functions, less wires, etc. Ever see how many wires go to the doors of an early 80s (pre-BCM) Cadillac?
