I found this on a different board, can't say if it works on the Fit as that board is for the Honda City (similar to the Civic). Figured it'd be worth posting as it looks promising. Link to full screen picture

EDIT: Found a similar thread in the Trix section. Mods, feel free to merge my post with that thread if it should be there.

 

Disclaimer: I have not actually tried this

I'm doing some investigation into this currently, and from my understanding, this is only part of the issue with displaying HDMI while driving. That wire, based on the schematics I found on here and also from techinfo.honda.com, comes from the parking/e-brake switch, and when the brake is engaged, it is grounded. This mod forces the computer into thinking that the parking brake is engaged all the time.

That all sounds great, except that if you put your car in any gear but "park" on the shifter, and engage the parking brake, you still cannot display video. Even though in the diagnostic menus, the parking brake signal is labelled "PARK-VIDEO" it doesn't seem to override the gear selector signal (which is unfortunately transmitted over the CAN bus to the head unit).

All said, I don't think this will fix it, but its still worth a try! I may give it a go this weekend, once it stops raining...

Anyone else feeling adventurous?

 

Looks interesting. I would try it but....im wrapped up into installing trailer lights relays and electric brake controller kit for when I tow a small utility trailer 5x8. I'm pretty sure im the only guy who will have this functionality on his Fit!

Keep us posted on the wire hack. Post a video if it works!!

 

Seriously, if there is a hack that can override the HDMI lockout, then the Fit just went from great to GREATEST EVER!

I mean, at the very least, the HDMI port would go from utterly useless decoration to one of the most useful ports to be found in a car.

 

I'm working on it for exactly that reason!

By the way, if anyone has a 6MT Fit, I'd like to see if the parking break works in the same way. It may be that only on the automatics that the parking break signal is ignored. If you have one and are interested in testing, let me know!

 

If someone attempts this and it works, I will definitely try it!

Two gripes with this method though: First, would it be different with the 6-speed? I feel like this would make it easier to override, but this leads into my second issue:

Would the speed sensors still cause the system to lock-out functions like this? I've noticed that the system will prevent functions like reading texts once the car starts moving, so that leads me to believe that the issue might not be solved by just grounding the parking brake wire. I have yet to try the HDMI input on the Fit, so I'm not sure what will lock-out the screen mirroring (brake versus speed), so if I'm wrong please correct me.

EDIT: Found out that I'm right. According to zeusmoltar (Post 17 here), once the speed activates the door locks, the screen will shut off. As he states, it is tied to two systems.

 

I believe those two function are different, considering how the HDMI port locks out when the transmission is put into gear rather than the car travelling at a certain speed. If we are able to trick the system into thinking the car is in park all the time, video would work, and all of the options may be enabled as well. Testing will tell.

esnave09, do you have a manual transmission Fit?

EDIT: Well it would help if I had read that thread completely. It looks like we both need to tell the system we are in park AND that we aren't moving. Interesting....

 

Yeah, I have a 6-speed. Only compromise so far versus the CVT is lower MPG on the highway.

 

I wonder if something like this would help keep the screen from turning off?

Speed Lock System Honda 2014

 

That's interesting, but I'm not sure what it does. Does it prevent the doors from locking at speed, or does it automatically lock the doors at speed? I can't tell from the description....

 

I can't tell either, but it might do both?

 

I found some other products that have similar names and it looks like they sense what gear the car is in and the door locks respond appropriately. Meaning, when the car is put into drive, the doors lock, and when it is put into park, the doors unlock.

Unfortunately I doubt this will make a difference. Only nice thing would be to see what CAN bus commands it looks for when the gear changes, but I can obtain those with a little effort myself.

 

I'd avoid it... whenever I see a product (or hear a speech) that is excessively vague and spits out big words/terms that don't amount to anything, I turn the other way.

At best, from the 3rd picture (the one of the back of the box) it looks like it's set up to replicate the factory auto-locking doors when it hits a certain speed. Doing a google on Nippon Power, you get other, similar devices that lock when you put it in drive and unlock when in park.

edit: oops, took to long to type... anyway, I wonder if the unit has a VSS wire. It could be that the unit reads the speed from the VSS wire and locks down the HDMI after the same threshold as the auto door locks

 

After thinking about it for a bit, there would be no way for it to disable the built-in "lock at speed" function. The only way to accomplish that is to block the signal coming from the ECU (or whatever controls it) from going to the other hardware, and there is no way that a slave device on the bus would be able to do that.

The only way it could work is as follows:

Doors unlocked -> Car gets to speed limit -> Doors lock -> device unlocks doors

I don't know what happens when you try and unlock the doors manually at speed (do they lock again?), so even that route might be blocked.

If by VSS you mean "vehicle speed sensor" or something like that, only the Navi unit has an input for that. The signal is called "VSP" in the honda manuals, which stands for Vehicle Speed Pulse. Seeing if that wire is connected or not to the head unit is actually their recommended way to see if the unit is Navi or non-Navi, which is interesting to say the least...

Side note: VSS stands for ground in the electronics world!

 

That's interesting that only the Navi models have the VSP. What do you think would be the control for that on the other models? Just wondering with the stuff I mentioned in my previous post with not being able to read texts and such after the car starts moving....

 

I'll bet you its done over the CAN bus. I'm not really sure why they would need a separate input on the Navi units, but I can say for sure it is not there on the non-Navi ones! I've poured over the wiring diagrams quite a few times now and its definitely not there.

 

Then, what happens if you disconnect the "VSP" wire from the navi?

 

That, my friend, is something I'd love for someone to test! That could possibly be the solution to this problem on the Navi units. I imagine you would have to ground the wire however.

The only concern is that the navigation app needs it for something, but only testing will tell us that.

One thing came to mind last night when I was thinking about this too: Some of these modifications, if done in hardware (CAN bus, VSP wire, etc), will reduce the functionality of the unit. For example: if the unit things we are always going 0 mph, the speed/volume adjustment will cease to function. Additionally, the reverse camera may not work on the automatics if we tell the unit we are always in park.

Hardware hacks might be a temporary solution, but I think all of this really needs to be done in software....unfortunately that is the more difficult route!

 

I agree that a hardware hack might affect a lot more than just the HDMI locking out. For one thing, it probably uses it for "dead-reckoning." Where, when the navi loses a GPS signal, it uses the VSP to assume how far you're travelling (though, can't account for turns).

On that note... I don't have a GK, so anything I say is simply on the speculation level.

 

Not only that, but according to the Honda docs, the Navi unit has (or has enabled) a gyro in addition to the speed sensor, so it can detect vehicle rotation for turn detection. The unit uses those two sensors to augment the GPS data, which may not be available all the time, for example in a tunnel or in an "urban canyon"

However, I do believe that the mechanism for turning off the display in either model will be the same, regardless of the presence of the VSP signal. It makes sense in terms of code reuse for whoever programmed the units. Obviously speculation, but its a logical assumption!

I'd love to post the full text from the docs, but I don't want to violate the TOS of techinco.honda.com. If anyone wants direction and has a subscription, I'm happy to show you where to look though!