Speed Sensor Disconnect for Nav Unit

BernieB · 07-23-2010, 06:50 AM

I've seen a number of posts to cut the speed sensor wire from the rear of the nav unit so it can be operated at speed. 2 questions:
If I disconnect it, will the manual transmission "speed matcher" for shifting be affected and where is the other end of the wiring harness if I don't want to have to pull apart the whole dash. It would seem to be easier to get to that wire somewhere else along its run.

kdochert · 02-01-2011, 12:45 PM

I have the same / similar question, I'm interested in disconnecting this wire to give my passenger access to the many functions that are disabled whilst driving.

My question is, are there any downsides to disconnecting this wire that affect things like the Sat Nav or Synchro rev match?

I would assume not as Sat Nav uses GPS usually to compute speed etc, and I assume synchro rev match has seperate speed wire? But I hate to assume.

wheee! · 02-01-2011, 01:42 PM

There are a few threads that discuss this in length on the forum but the basics are:

Disconnecting the VSS wire at the back of the audio head will allow you to enter NAV guidance etc while moving. However, your NAV will not appear as smooth if you leave it disconnected as it will have to wait for updates via the satelite versus updating via the speed sensor wire.
Bottom line is, add a switch in line with the VSS at the back of the audio head and then "break" the VSS signal while you enter info, then "make" the connection again by switching back to normal mode.

read here for more info:
Plug and Play Bypass Kit (DVD, NAV and backup Camera) Discussion

kdochert · 02-02-2011, 08:34 AM

Ah sweet, thanks. I must have been searching with the wrong keywords as I didn't find that thread. This issue is currently my biggest and pretty much only gripe with this awesome machine!

wheee! · 02-02-2011, 10:29 AM

No problem. I love being able to use my NAV when I want to. And I also did the backup camera mod too, where I can see out the camera in any gear like when I pull nose first into the garage and want to know if I clear the garage door yet....

wheee! · 02-02-2011, 08:10 PM

This is the finished switch

This is the audio head side of the homemade harness

And this is the switch side of the harness with the Relay in place to break the VSS when the switch is forward activated.

Read the previous thread link for full details of the diode placement etc.

07-23-2010, 06:50 AM	#1 (permalink)
BernieB Base Member Join Date: Jul 2010 Location: Villanova, PA Posts: 8 Drives: 10 370Z Conv Bl Man Rep Power: 14	Speed Sensor Disconnect for Nav Unit I've seen a number of posts to cut the speed sensor wire from the rear of the nav unit so it can be operated at speed. 2 questions: If I disconnect it, will the manual transmission "speed matcher" for shifting be affected and where is the other end of the wiring harness if I don't want to have to pull apart the whole dash. It would seem to be easier to get to that wire somewhere else along its run.

02-01-2011, 01:42 PM	#3 (permalink)
wheee! A True Z Fanatic Join Date: Sep 2009 Location: Mod Capital of Canada Age: 57 Posts: 7,354 Drives: cars. lots of cars. Rep Power: 40181	There are a few threads that discuss this in length on the forum but the basics are: Disconnecting the VSS wire at the back of the audio head will allow you to enter NAV guidance etc while moving. However, your NAV will not appear as smooth if you leave it disconnected as it will have to wait for updates via the satelite versus updating via the speed sensor wire. Bottom line is, add a switch in line with the VSS at the back of the audio head and then "break" the VSS signal while you enter info, then "make" the connection again by switching back to normal mode. read here for more info: Plug and Play Bypass Kit (DVD, NAV and backup Camera) Discussion __________________ H&R / Stillen / Berk / HKS / Swift / Michelin / UpRev / SPC / Amuse Rep / Seibon / Fringe XVO / TWM / more... My Journal

02-02-2011, 08:34 AM	#4 (permalink)
kdochert Base Member Join Date: Sep 2010 Location: US Posts: 25 Drives: 2013 370z M6 T + Sp Rep Power: 14	Thanks! Ah sweet, thanks. I must have been searching with the wrong keywords as I didn't find that thread. This issue is currently my biggest and pretty much only gripe with this awesome machine!

02-02-2011, 10:29 AM	#5 (permalink)
wheee! A True Z Fanatic Join Date: Sep 2009 Location: Mod Capital of Canada Age: 57 Posts: 7,354 Drives: cars. lots of cars. Rep Power: 40181	No problem. I love being able to use my NAV when I want to. And I also did the backup camera mod too, where I can see out the camera in any gear like when I pull nose first into the garage and want to know if I clear the garage door yet.... __________________ H&R / Stillen / Berk / HKS / Swift / Michelin / UpRev / SPC / Amuse Rep / Seibon / Fringe XVO / TWM / more... My Journal

02-02-2011, 08:10 PM	#6 (permalink)
wheee! A True Z Fanatic Join Date: Sep 2009 Location: Mod Capital of Canada Age: 57 Posts: 7,354 Drives: cars. lots of cars. Rep Power: 40181	This is the finished switch This is the audio head side of the homemade harness And this is the switch side of the harness with the Relay in place to break the VSS when the switch is forward activated. Read the previous thread link for full details of the diode placement etc. __________________ H&R / Stillen / Berk / HKS / Swift / Michelin / UpRev / SPC / Amuse Rep / Seibon / Fringe XVO / TWM / more... My Journal

02-01-2011, 12:45 PM	#2 (permalink)
kdochert Base Member Join Date: Sep 2010 Location: US Posts: 25 Drives: 2013 370z M6 T + Sp Rep Power: 14	I have the same / similar question, I'm interested in disconnecting this wire to give my passenger access to the many functions that are disabled whilst driving. My question is, are there any downsides to disconnecting this wire that affect things like the Sat Nav or Synchro rev match? I would assume not as Sat Nav uses GPS usually to compute speed etc, and I assume synchro rev match has seperate speed wire? But I hate to assume.

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