steering wheel mounted controls - how to wire them

[wentzr]

Many MIMA users have discussed mounting the systems control (joystick and two buttons) on the steering wheel, but come to a dead stop when figuring out what to do with the wiring.

I'd like to take another look at this, shouldn't it be possible to pass the wiring for the joystick (i'm looking at using a spring loaded thumbwheel) through the steering column? The CVT's S and D buttons must go through here, so I can only imagine it could be possible.

Just looking for anybody's insight on this before i go experimenting and accidently trigger the airbag in my face...

thanks!!

[joecvt]

There is a way to do this wireless if you only need two buttons and not the MIMA joystick steering wheel mount. The optional steering wheel buttons of the Rosta cruise control kit should work. Besides the labels on the buttons, they are really just wireless switches.

I had to reprogram mine about a year ago (mine were no longer responding). I could have ordered just another wireless kit (I think for about $40) but as a long shot, the tech rep sent me instructions on how to reprogram the kit. I did this with the kit out of the car and in checking for success, I could use a meter to verify function (with the kit as a stand alone unit) so the Rosta curise control unit itself is not required if you wanted these buttons to do something else (like remote MIMA switches)

And the look is pretty much like stock.

JoeCVT = Just your average CVT owner

[wentzr]

Hey Joe! Thanks for your post.
I'm not against trying wireless but only if I could transmit ALL data from, say, three buttons, a uniaxis joystick and a springloaded thumbwheel.. No particular application, just wondering

Still for me I'd like to try to keep this discussion slanted towards figuring out how to send wiring through the steering column. Personally I'm not a fan of wireless.. Its just flimsy and I don't want to use batteries if I don't have to, unless of course they're the batteries in the back of my car. I did find a thread on here about how to remove the wheel... I might just take my chances, go out now and give that a crack instead of stay up wondering!!

[joecvt]

Originally Posted by wentzr

Personally I'm not a fan of wireless.. Its just flimsy and I don't want to use batteries if I don't have to, unless of course they're the batteries in the back of my car. I did find a thread on here about how to remove the wheel... I might just take my chances, go out now and give that a crack instead of stay up wondering!!

No problem....Just thought that it would spark an idea for a different approach. The battery in the remote buttons lasts for many many years as it is only used when the button is pressed down. It is the type of thin round wafer type battery that you see in computers and such. The receiver unit is hooked up to 12v when the key is turned on.

However, it seems like it you want all of the MIMA user input signals on the steering wheel so off the shelf wireless may not be an option anyway.

A cable reel is used inside the steering wheel to connect the components together and allow rotation of the steering wheel. Unlikely will you have leftover wires available in the reel for your whole project.

The cable reel assembly for the MT model is shown here:
Honda Automotive Parts

(only $43 dollars)

The CVT cable reel assembly is shown here:
Honda Automotive Parts

($155 )

So the CVT model uses a different part number for the additional buttons on the steering wheel so I doubt that you would have any spare wires to attach to for MIMA and certainly not enough for all MIMA inputs.

Perhaps you can use the part of the steering column where the combination switches are (like lights and turn signal levers). Still within reasonable distance from the steering wheel and no rotating parts to deal with.

Be careful around the airbags and do not power up the car with the air bag disconnected as you will probably get an SRS error code that may not be cleared so easily as others.

JoeCVT = Just your average CVT owner

[wentzr]

Thanks Joe, I really do appreciate the ideas!

Do you know if that assembly is metal or plastic?? I was able to peer into my steering wheel last night but unfortunately i stripped the head of one of the torx t30s.. they REALLY don't want you removing that airbag... of course it didn't help that the steering wheel only locks at 3:00 and 9:00, making it impossible to get to those T30s from the side... arg. Well, it coulda been worse. At least I didn't get punched in the nose by an airbag.

If the assembly is plastic (or a drillable metal) I might attempt to "easy out" the T30 (after i find and try a T30+ bit) so i can drill a passage through that assembly for the joystick/buttons assembly.
(edit: ok, so my memory of the assembly wasn't so good.. I just checked it out again... aint no way I'm drilling through that! only option is to use the existing connections in the cable reel)

Of course if the column proves in the end to be 100% impassable and tapping into the pre-existing circuitry doesn't work (if i was able to live w/ just a joystick on the wheel, could i get the 5V from one of the wires going to the s/d buttons?? if so I'd only need 3 more wires, and at no time would the s/d buttons be used at exactly the same time as the joystick)... well then and only then will i go with wireless. I'm researching DIY RC in the meantime as my backup plan.

Thanks for sharing your ideas on this, Joe. I really appreciate that this community is still as active as it was when i first got my insight in '04.

[joecvt]

Originally Posted by wentzr

Of course if the column proves in the end to be 100% impassable and tapping into the pre-existing circuitry doesn't work (if i was able to live w/ just a joystick on the wheel, could i get the 5V from one of the wires going to the s/d buttons?? if so I'd only need 3 more wires, and at no time would the s/d buttons be used at exactly the same time as the joystick)... well then and only then will i go with wireless. I'm researching DIY RC in the meantime as my backup plan.

According to the electrical manual, a common ground wire goes up through the cable reel to the S/D switch and then two wires (one for S and one for D) go back down through the cable reel to the TCM. So there is no 5V present at the switches at any time. The horn is the same type of setup with ground being the contact at the switch.

JoeCVT = Just your average CVT owner

[wentzr]

Did some research and found someone did something similar to what i'm trying to do w/ a Ridegeline... here's the thread

hmm.. I'm going to take a look at this reel assembly. I got my head down by the foot pedals and checked to see how many "used" wires are going into those connectors. The farthest connector to the right going into the the wheel assy had 5 open spots for sure. Thats enough for a joystick and joylock, which I could live happily with.

Looking at the diagram on the link you sent, Really the cable reel is all i'd need from the whole assembly, and the connectors on the harnesses for both the CVT and manual are identical as far as I can tell.. i might get away with that $43 price tag after all if i can't find just the sub-wire cable reels individual. I could wire my button and jstick wires into the open connections, and wire the other side to my joystick controller card. . .

hmm.. the wheels are spinning. Now, first i'm ordering a replacement torx t30... of course on honda's diagram they have it labeled wrong as a hex..

Side note, i noticed when i start up my car after reconnecting the battery, (this happened identically, twice) the electric battery indicator in the dash is empty and the car immediately goes to three bars of regen (this car is currently un-modded, FYI)... I drive for about a mile and finally get a bar of battery, then i come to a stop sign, it pops to two bars. about a block later it gets to three bars, then assist is enabled... about 10 seconds later, every 3 seconds i get back another bar of battery, until it displays full bars. I think last night when I parked, the battery had a full charge, so i'm wondering if this is just the car's computer waking up to reality.. is it a good idea to drain some juice by going up some hills or something before disconnecting your battery to avoid a potential overcharging of the battery??

Considered starting a new thread, but this is relevant as anyone messing with the current topic will run into this and might wonder the same thing i'm wondering. I can't imagine it's good for the battery pack to be going through this constantly.. eh?

[joecvt]

According to the electrical manual (that shows what each pin on the connector is for), I see two connectors for the cable reel:

Connector A: Two pins - both for the airbag (I would leave this one alone)

Connector B: Four pins - pin1 = Ground, pin2 = horn, pin3 = Sport mode, pin4 = Drive mode

Just to make sure, do you have an MT or CVT? If CVT, there are no extra pins that I can see. If MT, you may have two extra slots available for potential pins but not sure if an MT cable reel will have all internals needed. There must be some reason why they sell a different part number cable reel at additional costs for the CVT (although two extra cables in the reel doesn't seem to justify triple the cost )

The SOC going to empty is normal when you disconnect the battery. It is the same as doing an MCM reset. On initial power up, it has to charge the battery a bit to determine what it thinks the current state of charge. It will do this every time you disconnect the battery or remove fuse 18.

I wouldn't want to do this every day but it shouldn't cause any long term issues by disconnecting the battery a few times to do the modifications.

JoeCVT = Just your average CVT owner

[wentzr]

Originally Posted by joecvt

According to the electrical manual (that shows what each pin on the connector is for), I see two connectors for the cable reel:

Connector A: Two pins - both for the airbag (I would leave this one alone)

Connector B: Four pins - pin1 = Ground, pin2 = horn, pin3 = Sport mode, pin4 = Drive mode

Ok, this is correct, there are two connectors, but those two connectors plug in side by side into a socket in the reel assembly. This should make sense with a quick glance at the diagram of the reel assembly... you can see the other ends of those two connectors plug in side by side into a socket in the assembly. That socket in the assembly has more than six pin connections. I'm still at work so i can't check this again ATM but if there are six known used wires and I saw at least five open spots, and we can tell by looking at that diagram the socket is certainly wider than three pins... i'm fairly certain that what we've got is a 12 pin connector to get into the steering wheel, with six open pins.

Really i shouldn't need to purchase any more connectors, I have everything i need if i could get into my wheel now!!

Yes I am aware (and being incredibly careful) of the dangers with working so closely to the SRS. If I were a skydiver I wouldn't want holes in my parachute either! I'm being very careful, and so should anyone looking at modifying anything on the steering wheel!! I will turn back the moment I feel the SRS may be damaged by this mod.

[JimIsbell]

Make sure you get pictures and drawings. I really want to see what you find so I can do something similar on mine.