So I had my parking brake module fail a year or so ago. It stuck on one night and I couldn't drive to work the next day. I grabbed one of my other cars and diag'd it later. Well, I bypassed it. I had tried replacing the module with another (used) unit of the same part number hoping I wouldn't have to reprogram it but that didn't work. I wasn't going to buy a brand new version because my local jag dealer said they couldn't work on anything older than '08 and there was only one specialty shop in the area that said they 'might' be able to program it. That's a big outlay for no guarantee of fixing it. Well then I swapped out the auto box for a manual transmission and have just been leaving it in gear or making sure I park on flat surfaces. That's just not acceptable. It just makes the swap a halfass one that I'm not proud of.

A week or so ago I had an epiphany. I could use a small arduino to replicate the functions of the parking brake module without the hassle of trying to find a way to program the stock one. Well that was easier said than done. I made the mistake of thinking the parking brake switch in the center console was like most other switches that either sent a CAN signal or kicked 12v/5v down a wire and the module did it's thing. It doesn't do any of that. The switch actually uses resistance to trigger the parking brake. At rest, both the engage and disengage circuits see around 610 ohms. When you push or pull the switch one wire or another drops down to 150-ish ohms and the module knows to engage or disengaged the parking brake.

I threw together a little tester with screen to see if it would all work.

Boom! The arduino reads the switch wiring, when it gets between 150-160ohms it kicks on one of the relays to power the motor. I used a big relay assembly for testing but I'm going to see if I can use a smaller one and fit the whole shebang inside the stock EPBM case. There are a few really small CANbus interfaces as well. Would be nice to eventually include a connection to the SCP network for some extra safeties (eg don't engage while vehicle is moving) or automatic features (eg auto engage/disengage on vehicle start/shut down).

I'll try and remember to update this once I get it wrapped in the stock case.

 

Thats great info thanks. Looking forward to your update , is your car a 3.0? I have a factory 2003 manual

 

I bet you are really enjoying the manual in the str. Burnouts are normal procedure i am sure

 

hi
the oe modules are plug and play if there off a similar car, same engine and gearbox.
there quite easy to program if they dont work, with jaguar ids/sdd.
the auto release would be nice, I never use the manual release in my car
also the handbrake should engage whilst moving, its there as a backup emergeny brake, if I remember right, every time you pull it whilst moving it pulse on, once pulled 4 times, its fully engaged, any time you hit the accellerator it should release
the original module is quite smart, there a reed sensor that remembers position and also motor current is monitered, it does not fully power on, it get to a positiion and stops, at a certain current 15amps fully applied, to increase motor life and also does not fully wind off, returns to a set position when brake is off.
cheers
Joe

 

No, I've got a v8 car. I would've loved if it came factory with a manual trans.

Haha, As it is right now I'm too ashamed of the one wheel peels to really enjoy burning out.

I had heard they were supposedly plug and play with proper numbers/options but I did not get so lucky. And have had no luck with getting a functioning ids/sdd system setup for a reasonable amount of money. Yeah, there is a feedback circuit for motor position that I may play around with to get a "smarter" brake but for now a functional "dumb" brake is good enough for me.

 

Forgot about no lsd. I have an R but auto of course. A manual like yours definitely needs an lsd

 

Well after successfully bench testing the breadboard unit I tried to miniaturize the circuits and fit inside factory module's case.
(I had a picture of it all tucked in the case but for some reason trying to attach the picture it stops @ 90% upload)
I plugged everything into the car and got bupkis. Damn. I messed with things and still got no functionality. I got really frustrated and took my breadboard prototype out to the car and wired it all up and it functions perfectly. Sit in the car and engage/disengage the brake no issues. So obviously my attempt at miniaturization failed. Ha. Time for ver2 of the board. I really want to get it inside the factory case for plug-n-play.