Vehicle Speed Pulse Width Signal

Hello, I've been working on installing an 86 radio into my 2001 SR5 Tundra. So far I have a factory 86 microphone working as well as the usb and aux as well as a Tailgate Masters rearview camera. I'm trying to get the factory GPS to notice the truck's speed, however i haven't been able to find a pulse width signal to tie into the radio for vehicle speed. Has anyone received a vehicle speed input for any double din radio?

I'll take any information on the 1st gen tundra, from 2000 - 2006 as it will give me a good base to try to figure this radio out.

 

Welcome to the community!

@empty_lord has done extensive work with the 86 radio. I want to say @assassin10000 also may have one. I have one on-hand but it's not fitting my audio needs, so I've skipped install and stuck with the Alpine W650 I've got (and will ultimately move to the W770 in the future for wireless CarPlay).

That said, my truck is an '06, and it had an addition plug tucked in the back, behind the radio, with two wires. One of them is the vehicle speed wire, IIRC. In our community support megathread for new owners, there's a whole section on Audio. Looking in the "what adapter harnesses to buy" in the audio section, I found this pic I marked up helping another member in a linked thread. It shows the speed harness/sensor I also had in my truck. It was taped to another harness in the back of the dash, so it wasn't readily visible at first. Note the grey connector, and I want to say the speed wire is green w/red stripe? We have links to the EWD on the 4th or 5th sentence of that community support thread I linked above.

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I do.

See @shifty` s post above. I used the speedo signal off that 2 wire plug. This only applies to later years.


For the earlier models you'll have to take the signal that goes from the cluster to the ecu iirc.

 

I did have the thought of the signal being translated by the ecu. I'll have to trace several wires at the junkyard, see which wires go to the ecu and which go to the speed sensor by the transmission. and see if I can make a bridge that I can splice on to. Thank you guys it gives me a bit of direction of where to look.

 

Here's the EWD for your 2001, other years will vary, but this will help you trace the correct color wire to tap: https://www.tundras.com/attachments/2001-tundra-ewd429u-pdf.543918/

 

Thank you for the EWD shifty` the diagrams helped with locating what I needed. Wanted to follow up on finding the VSS for the early Tundras. I used the EWD to find where the VSS from the cluster goes to which ended up going to Junction J7. I found J7 and saw that it branches off to different areas: integration relay, ECM and a loose connector which i only assume to be the 4WD ECU. I would have spliced into the 4WD ECU, however I've been consecutively finding rs3000 wiring harnesses on 2002 Tundras at the junkyard, which I ended up splicing into the bridge between the rs3000 and integration relay. Now the GPS signal is fluid and accurate and will be used as another form of navigation.

PS: One of the good things about the RS3000 as opposed to the KARR system that the dealer installed is that the key fob is still available new as part number: PT398-07101.

 

Nice!!

 

Great job tracing all that out. I'm needing to find this very same thing to wire my new Alpine iLx-507. I'm hoping you can tell me if it matters where I splice into the Green w/orange striped wire. If I'm looking correctly it comes directly out of the fuse panel by driver side and runs across dash to pass side ECM . I'm thinking I have to wire it after the ecm to the junction to 4 wd control? I'm new here and I have to say I've read many posts and find so much knowledge on here. Special thanks to Shifty , who has helped much already without ever having met me.

 

I guess I'd like to understand why you want to tap into that wire? With stereo installs on these trucks it's almost always 100% unnecessary to:

• Tap into a reverse trigger on the Tundra's factory wiring
• Tap into the e-brake lead to unlock your head unit

If you're asking because you want to install a backup camera...

Have you seen this?: https://www.tundras.com/threads/wha...-gen-tundra-today.2558/page-1624#post-3199439

And also this may be helpful for a simplified diagram: https://www.tundras.com/threads/1st...-unit-whos-got-what.65309/page-9#post-3245097

Whatever you do, when tapping off OEM wires, heed this warning:

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Crutchfield sent me the posilocks. (I didn’t even know they existed. Back in the day everyone used the scotch locks) I contacted Dave for a Reverse T harness to tap into the rear tailgate . I also need help that I’m installing the bypass correctly. I contacted the company and they said the newer Alpines don’t need the 4 wire bypass and the 3 wire I ordered would work.
I thought I was better at this when I was younger.

 

I was thinking since the Alpine head unit comes with GPS antennae it would also display the vehicles speed on the screen with the voltage that’s displayed.

 

I also forgot the main reason I want to hook up the speed wire! (getting old sucks) Because this Alpine is telling me I cant use the functions while the vehicle is moving. I get no video unless brake etc but no rear front speaker fade control?? left right I can do but certain functions are off . Being that it didnt say parked it said moving I thought it needed the speed wire to tell it 0 mph.

 

"While the vehicle is moving" is a function of e-brake lockout/engagement, not speed. I think you're overthinking this, heavily. PAC bypass or similar will fix that. The part number is TR-1, here. Install instructions come with it, it's super easy to setup. It's what I have on my Alpine iLX.

You don't have speed into your dash for your year. I think that's an '05+ only thing, but maybe it is in earlier years? See reply #2, smallest red circle. 5-pin harness. Contains a reverse trigger wire and speed wire. I don't remember whose post I stole that pic from, someone who had an asshole previous-owner that hacked up his OEM harness. But I think they were driving an '04+ truck.

 

FYI, for install, though with a lot of radios you can simply ground the parking trigger wire on the radio, I don't recall if it works with Alpine or not, it does for Kenwood/JVC and quite a few others:

https://www.youtube.com/watch?v=TpQUKdfED34​

 

That makes sense ,Shifty. I have the PAC bypass and I installed as shown on that diagram in my picture but It doesn't even light up. What makes it worst is I bought an open box from Crutchfield and now I dont know what is wrong. I know this is going to be a dumb question, but can the PAC bypass just connect to the wires on the radio and not to the car? In other words, I dont need to tie into the actual parking brake wire? just the wire coming out of the Radio marked Parking brake? For some reason I AM overthinking everything. Surely you can have a rearview camera operate on a table top by connecting one lead (-) to ground and both wires, trigger and )+ lead, together to power +. (Of course It would never shut off until trigger is disconnected). Trigger only being momentarily on when called for (as in reverse).

 

I feel like the video I just posted answers your questions. If not, let me know what's different, and tell me the model number of the bypass you ordered. My bypass doesn't light up, so I'm not sure what you're talking about.

Again, I'll reiterate : For parking brake bypass, you should NOT need to tap into any OEM wiring. Likewise, for reverse camera, the only wires you should need to tap into are the reverse light wire, which you can Posi-tap off the back of the driver tail light (and ground there too). You don't need the DIR harness, DIR just gives you a cleaner, no-Posi-Tap way to get there.

 

I was able to get the radio working with the bypass correctly wired. It seems I had it wired incorrectly. it had to be the correct black and yellow and blue, duh. ."No more vehicle must be stopped" to access the main setup screen in lower right.
Thank you for all your help Shifty. I greatly appreciate you helping to redirect my focus and providing the video.

 

Thanks for being patient and sticking in there! Sometimes all we need is another pair of eyes.

 

Shifty, so I went to diybypass.godaddysites.com and the Second video from top titled "Product Demo" shows it being Lit when the radio turns on. Since it looks exactly like the PAC, I assumed it's the same. Anyway, it lights up and I asked for help and the guy responded pretty quickly to a live chat.

 

But to be clear, it was your redirection that lead me to the promised land! Thanks again.