Locating "speed sensor wire" for CarPlay stereo hookup ('01 XtraCab)

[Solved. See followup post below. The pics in this post do NOT show the correct wire. -Dan]

I'm trying to find a speed sensor wire to connect to a new stereo receiver I'm installing. (Apparently Kenwood holds the wireless CarPlay functionality hostage until you get both this and the parking brake switch hooked up.) Crutchfield tech support describes it as “green/orange speed sensor wire, pin #21 of 28 pin plug at ECM behind glove box”. I'm clueless, but I pulled the glovebox bin, and the trim piece above the bin, wherein I found a large connector with at least one wire that could be described as green/orange (could be the one at the top left of the second picture).

Am I getting warm?
Thanks,
Dan

 

I believe all that’s looking for is ground. I know at least the parking break sensor wire on the stereo needs a ground signal, not sure about the speed sensor.

All you need to do is find a bare metal surface to trick it.

 

I think you’re right the brake can be bypassed to ground, but not the speed sensor. I gotta find that wire. Anyone?

 

So speed sensor isn't just looking for ground like the park brake? I think Barto is on the right track

 

I made this connection from the back of the Combination Meter. On my truck it is a light green with black stripe wire (LG-B).

 

I agree with the last post. On at least some modrls Toyota likes to take the analog speed sensor signal fed to the speedometer and convert it (in the speedometer) to digital (square wave) to be sent to the computer. You can intercept the wire coming out of the cluster.

If the stereo has a navigation system it uses the speed signal to calculate your speed more accurately and quickly than just using GPS. It automatically calibrates the speed sensor signal to speed based on GPS calculated speed, then uses the speed sensor signal after that. Doing this, it doesn't need to know what kind of car or tire size, etc.

 

I'll also recommend posi-tap to splice into that wire. It makes it a lot easier than trying to cut wires and crimp or solder in the cramped dash area.

https://www.posi-products.com/posiplug.html

 

Wait... Am I missing some features on the Kenwood I just installed?

I'm using Android Auto... Mine seems to be working, but I don't know if I'm missing something because I have nothing to compare to.

I just hooked up with wiring harness adapter to the stereo wires and plugged it in. The only wires I had left over was the remote (because I'm not running an amp) and the power antenna (because I don't have one of those either).

 

I've never liked those lame cheap ass splice connectors so never wasted my time looking for a good one. I never knew these existed. Gonna have to order some

 

Thanks for your help, everyone. I found the wire I was after and my Kenwood is working correctly now. Some follow up points:

- It's true, just grounding the parking brake wire worked fine and was much easier than either of the places Crutchfield told me to connect it. (To be clear, they were very helpful to me over all.)

- No, the pictures I posted in the original post do NOT show the VSS (vehicle speed sensor). See new pictures below. The correct wire was right where Crutchfield said it would be, but it took some digging for someone like me to find it--I didn't even know what an ECM would look like. I had to remove the glove box bin and also the "ceiling" trim piece of the glove box. Then I had to pry open some flexible plastic split conduit to reveal the wire. I chose to cut some of the conduit away to make more room to tap into it. Yes, they also told me I could find the same signal at the instrument cluster, but I didn't have to go that route.

- At first startup after connecting these last two wires, while still parked, I got the same error message as before (to paraphrase: "Wireless CarPlay requires VSS and Parking Brake wires to be connected"), but I think this was just left over from before. Once I pulled out and drove a short distance at speed, the VSS signal “lit up” (I assume) and after power cycling the stereo CarPlay works perfectly now.

Thanks,
Dan

Glove box with bin removed and "ceiling" trim piece hanging at lower right:

Close up of pink VSS wire from Kenwood tapped into green/orange VSS wire at ECM:

 

Awesome man! Thanks for following up and with pics to make it easier for the next bloke

 

Hooking to the vehicle speed sensor (VSS) is only necessary if the stereo unit also has built in navigation software that uses it. Without built in navigation there will be no wire for the VSS.

I don't think Android Auto would use the vehicle speed sensor even if it was available in the stereo, but maybe it would if it was common on newer cars, I'm not sure.

 

Not so, although I definitely won't try to defend the logic of *why* it isn't so. My receiver is the Kenwood DDX9906XR, which does not have built in navigation. Nevertheless it has a GPS antenna, it has the pink VSS wire, and CarPlay would not work *wirelessly* until the VSS wire was connected correctly. (CarPlay worked via the USB 2.0 connection without the VSS wire connected, exactly as described in the error message on the Kenwood screen.)

The best logic I and the Crutchfield tech support person could come up with is as follows (all speculation, i.e. untested by me):

- VSS & the unit's own GPS antenna/radio improve the accuracy of positioning viewed via Apple Maps or Google Maps, or both.
- Kenwood doesn't want you using certain of its native features while rolling, for safety reasons.
- Kenwood holds wireless CarPlay (the unit's marquee feature) hostage until you get VSS connected.

It's a very new product from Kenwood. Crutchfield does not yet have the detailed user manual, only the quick start manual that ships with the unit. I sent details of my solution back to Crutchfield in hopes that they incorporate it into their installation instructions in the future, or at least arm their tech support staff with the information, because they'll surely be getting more calls from yahoos like me. I imagine the pro installers will be able to cope with or without detailed instructions.

Dan

 

Thank you for correcting me. I didn't realize the phone apps used the speed sensor info.

The user manual showing where to wire everything for your unit is on the Kenwood support page. Seems like Crutchfield should should have all the info they need.

And how could someone install this on an old car without a speed sensor? I guess they're SOL?

 

I still don’t know if any phone apps really use the signal—we were just speculating.

The Crutchfield tech said she could see the link to the manual on Kenwood’s site but it wouldn’t load for her, and it was new enough that Crutchfield didn’t already have a copy, digital or otherwise. I don’t know if that manual explains how my unit uses the VSS signal. Maybe, but my focus wasn’t on solving that mystery, just finding the VSS wire on my Tacoma. The Kenwood manual wouldn’t tell me that.

As for old cars with no VSS, I found a YouTube video from an outfit with a solution to that very problem: a $100 product that consists of a tiny gps radio and antenna along with a circuit that uses the gps info to generate a fake (but realistic) VSS signal, solely for the purpose of connecting to receivers that require that signal.

 

Hi whizfish-What is the name of the company that makes that VSS workaround gizmo?

 

https://youtu.be/5FMimfxShJY

 

I know that this is an old thread, but I have found it interesting in that I am currently installing a Kenwood DDX8906S stereo into my 1997 Tacoma and ran into the VSS wire issue. I actually think I found the VSS wire, but wanted to make sure of what I was doing so I called Crutchfield support to make sure. They told me that I no longer needed to connect the VSS wire if I applied the latest software update to the Kenwood stereo. I also just looked at the comments section of the YouTube video that was posted earlier in this thread and saw that this was also the case.

The Crutchfield support associate did tell me however that I DO need to connect the Parking Brake wire to make things work properly. Has anyone else found this to be the case?

 

I'm the original poster of this thread. I've installed 3 similar Kenwood stereos now (2 in Tacomas, 1 in a Prius), including the one that motivated this posting. The newer ones (probably just updated firmware) no longer require a vehicle speed sensor connection. They DO still require that the parking brake wire is connected. However, simply grounding that parking brake wire from the stereo works just fine.

 

99% true, I've read that some stereo-cos have gotten wise to the pure ground, in which case you need one of those bypass jumpers (https://www.amazon.com/MicroBypass-Parking-Override-Bypass-Kenwood/dp/B005SVXQS4).

Either way is way easier than getting it attached to the PB