Remote frunk release

[Snelbaard]

I use my MR2 as a daily driver. For this reason I have taken my spare tyre out of the frunk, so I maximise what little cargo space our cars have to offer. After fitting gas struts to the frunk, it appeared to me it would be convenient to be able to pop the frunk with the key fob. You wouldn't have to dive into the glove compartment every time you wanted to drop some bags in the frunk.

I started exploring how I would make this work. The mechanical aspect is easy enough: there are plenty of door release actuators on Ebay. I'll have to install one somewhere, should be doable. Also I found that the key for a Toyota Avensis is exactly the same as an MR2's, only with a hatch release button. It should be possible to transfer the blade of my key to the housing of an Avensis.

But now for the difficult part: The car would have to know what to do with the incoming hatch release signal. I know nothing about electronics so I hope you'll be albe to give me some pointers. I know that there's a receiver in the car which relays to the Body Control Module (BCM), which then opens and closes locks and things like that.
Is the BCM programmable in such a way that one could just add frunk release functionality? Or would it be possible to replace the MR2's BCM for one out of an Avensis? Or is there another clever way of going about this? I'm anxious to hear your thoughts.

[Carolyn]

I have a remotely operated isolating relay on my silver car.  I used a fob and receiver designed for controlling winches.  There are other fobs and receivers and solenoids out there that will do the job.  That way you don't need to mess with the key or the ECU.

However, the frunk also has a safety catch.  Are you proposing to remove this? If so, an un-noticed accidental operation of the fob could result in the front flying up and doing immense damage, possibly even causing an accident. 

So my thought is:  Possibly not the best idea?

[Snelbaard]

No, naturally I will keep the safety latch.

[Topdownman]

I had my bonnet come open at speed on an old escort van I had.

It happened to be again a few years later in a seat ibiza.

Of course, I was getting used to it by then.....

[mr9]

I've also thought about this. I'm fine opening the front from the safety latch but having to open the passenger door then glovebox then pull the latch really limits the practicality of the car.

[Call the midlife!]

Can you not just take a power feed from the door lock circuit to control your proposed frunk solenoid?
Granted the doors would also unlock but you're going to relock them when you lock the frunk.

[paulj]

Can you not just take a power feed from the door lock circuit to control your proposed frunk solenoid?
Granted the doors would also unlock but you're going to relock them when you lock the frunk.

That gets my "simplest is best" vote.  And now I think about it my BMW unlocks all doors when you pop the boot so you'd be in good company!!

[Call the midlife!]

Can you not just take a power feed from the door lock circuit to control your proposed frunk solenoid?
Granted the doors would also unlock but you're going to relock them when you lock the frunk.

That gets my "simplest is best" vote.  And now I think about it my BMW unlocks all doors when you pop the boot so you'd be in good company!!

Don't want to wander off topic but depending on what model BMW you can change the settings in IDrive for what happens when you press the fob.

Mine's set to unlock driver's door only on the first press, another press to unlock the rest.

[mr9]

Can you not just take a power feed from the door lock circuit to control your proposed frunk solenoid?
Granted the doors would also unlock but you're going to relock them when you lock the frunk.

They means you'll have to realise the front every time you use three car though

[Call the midlife!]

Can you not just take a power feed from the door lock circuit to control your proposed frunk solenoid?
Granted the doors would also unlock but you're going to relock them when you lock the frunk.

They means you'll have to realise the front every time you use three car though

Yeah, fair one, I'd overlooked that version of events 😂

Unless there's a way of fitting a hidden release handle in the front bumper to work similar to the door locks?
So the solenoid unlocks the latch but you pull a handle/push a button to actually release the mechanism, like the doors.
A generation of Fords had locks behind the blue oval badge in the radiator, you swivel the badge out of the way and use your key to open the bonnet latch but it's also linked into the central locking.
Or like in my case it seizes up so you drill the key barrel out and use a long screwdriver to work the release, it's a common "mod"...😂

[paulj]

Placed my vote too early, didn't I......

[mr9]

Make any progress on this through lockdown?

[Snelbaard]

None at all. This is quite a low priority project for me. Also I'm sure there relatively simple ways of achieving this, but I insist on using a Toyota Avensis keyfob. I'm going to have to immerse myself in the world of electronics to make that work, so I procrastinate.