johnp66

Anyone having success getting the AVIC-Z1 to recognize the speed sensor on a GS400? The installer wired the unit to the green wire in pin six as instructed by DaveGS4, who has a '98 model. He tried both green wires on opposite sides of the harness. No luck so far.

After driving it for a week, a pulse registered every half mile or so and grew to 285. It should cycle from 0 to a higher number and then back to zero. The installer said he checked the wire with a meter and got nothing. Not sure there would be voltage unless it was moving.

He is experienced and spent several hours working on it as I watched, trying virtually every wire in the harness. Speedometer works fine and I assume that means a wire is feeding it a speed pulse signal from the transmission.

At this point, it appears the 2000 is wired differently than the earlier models, or the signal is too low to be recognized.

The unit works only in simple hybrid mode, but you lose dead reckoning and precision with the mapping. This can be checked on Hardware settings menu.

johnp66

Just to close the loop on this thread .... The installer removed resistors in the Z1's VSS and rear brake wires and the system is now running full 3D hybrid mode. He said he used a "purple and white wire" for VSS in the power steering control unit between the kick panel and the ECU.

This differs from the hookup described here on CL for '98 and '99 GS4s. This should be verified on your particular model before connecting. I expressed concern about removing the resistors, and he said he checked the VSS wire with a meter to make sure it wasn't hot. Proceed with caution here. And I'll update if I experience any complications.

This is a really slick unit with voice commands, dead reckoning and a quality audio front end. I unplugged a Pioneer P9 and the performance is very comparable. The routing is sometimes weird -- not nearly as good as the Garmin 2160 on my HD Ultra. The Z1 supposedly learns from your route history, and it will be interesting to see if that helps down the road. Of course that wouldn't be much help in unfamiliar areas -- and why would one need routing in familiar areas?

But the voice commands makes it much safer on the road -- and hearing the actual street name is a big improvement over my 2610, I do miss the "next road" feature on the 2610.

Also, I now have the Z1 absolutely flush-mounted in the GS400. With the custom Lexus logo display screen (and the menus turned off), it looks stock.

Spyder78

iTrader: (7)

I am a lil confused yes I do understand that the way that davegs4 wired it inot the green wire. But the problem is that the wiring diagrams for all 3 years of the GS400 from the www.the12volt.com all correspond to the same wire refer to the tables below.

2000 Lexus GS300/400 Cruise Information
Tach Black/Yellow Module under Hood Driver's Side 28 Pin Connector Pin16
VSS Lead Blue/Yellow Pin 5 Connector E4 in Black Box Driver's Side of ENG

1999 Lexus GS300/400 Cruise Information
Tach Black/Yellow Module under Hood Driver's Side 28 Pin Connector Pin16
VSS Lead Blue/Yellow Pin 5 Connector E4 in Black Box Driver's Side of ENG

1998 Lexus GS300/400 Cruise Information
Tach Black/Yellow Module under Hood Driver's Side 28 Pin Connector Pin16
VSS Lead Blue/Yellow Pin 5 Connector E4 in Black Box Driver's Side of ENG


If this info is correct and I am pretty sure it is the wiring in all years of the Gs should be the same. I will let you know what happens when I get my avic n1 back from the upgrade and when I install it next week if this is true as I have a 2000 GS400.

johnp66

If I were doing it again, I would start with Dave's diagrrams. They also square with BananaGS's photos posted on CL.

My installer said he got the VSS to work with the purple and white wire in the steering control unit box. I believe the key was removing the resistors from the ends of the Z1's lines. Both the green and white wire and the backup gear signal were erratic with the resistors in place. The VSS would pulse every half mile and the reverse signal was on and off with the car in reverse.

I wish the installer had gone back to the green and white wire in the instrument cluster after he removed the resistor. Bet it would have worked.

No idea what the purple and white wire is in the steering box. He did say it turned out that his documentation for the GS400 was correct. Maybe blue and yellow looks like purple and white in the back of the floorboard using a flourescent lamp. Or, he may have been mistaken about which wire I was asking about, although I asked twice. I will see him tomorrow afternoon when I upgrade my GEX-900 to a GEX-920. I will pin him down for you.

But I wonder if others with 2000 models have hooked up their VSS wires to a nav unit?

Spyder78

iTrader: (7)

alright keep me updated.

corkycal

iTrader: (8)

would i run into this problem with an avic-d1 in a 2000 gs300? i know hameed installed his avic-d1 tapping into the green wire for his vss. again, i believe his gs400 is a 1999.

johnp66

I confirmed with my installer that he used the purple and white wire in the power steering control unit. He said the power steering is reduced depending on the speed of the vehicle, which it calculates from the VSS pulse.

When I offered my (totally uneducated) guess that the green and white wire might have worked once the resistors were removed, he said "probably." Obviously, the speedometer needs the same info and undoubtedly uses a VSS connector.

He did say that he looked at the 12-volt.com wiring details and that they were incorrect for my 2000 GS400. He laughed, saying he could not even find a bue and yellow wire.

Sorry, Corky, others will have to help you with the GS300.

corkycal

iTrader: (8)

any way you can take a picture of this purple and white wire? a picture of where it's located.

i'm going for the green/white wire first and if this doesn't work, i'm going for the purple/white but will need to know where it's at.

thanks for the info.

Hameed

You can't miss it bro :

http://lexusmodz.netfirms.com/GS_DIY/instrumentpanel/

johnp66

I don't have a photo of the purple and white wire. In fact, it might be quite a challenge to get a camera under there. It's between the kick panel and the ECU. But I assume you can find it with a pen light. I am betting on the green and white wire.

Spyder78

iTrader: (7)

tried the green wire no speed pulse. Drove around with the multimeter measuring voltage. The wire does change volts but my n1 doesnt see anything. What green and white wire are you talking about John?? On BananaGs site it says green wire is the speed wire. Help me out I gotta get this thing straight so I can put the car back together.

johnp66

DaveGS4 has excellent photos here. Photos are near the end. Say thank you, Dave.

https://www.clublexus.com/forums/sho...&highlight=vss

Spyder78

iTrader: (7)

Thanks John that did the trick. Funny thing is that i spliced into the wire on the bottom of the clip. they have the exact same wires top and bottom. Thank you once again, You saved me a big headache.

corkycal

iTrader: (8)

great info. this will save me and others a lot of time when hooking up their navi.