Vehicle speed pulse signal cable

Thread Starter

Zurikela

Joined Feb 25, 2018
3
Hi there, any idea how to locate vehicle speed pulse signal cable on the car?
Need to install head unit with the navigation
Thanks!
 

wayneh

Joined Sep 9, 2010
17,498
The crank angle sensor? I believe there also similar sensors on the transmission. It probably depends on the vehicle. Just google your make of car and “speed sensor”. Somebody will know where it’s located.
 

Thread Starter

Zurikela

Joined Feb 25, 2018
3
The crank angle sensor? I believe there also similar sensors on the transmission. It probably depends on the vehicle. Just google your make of car and “speed sensor”. Somebody will know where it’s located.
Thanks for replying.The unit i have to install has a mavigation and you have to connect the speed pulse signal cable to the vehicle speed pulse signal terminal, which in my opinion is somewhere under the hood. I tried google with my car’s model and year but can’t find any info
 

wayneh

Joined Sep 9, 2010
17,498
Thanks for replying.The unit i have to install has a mavigation and you have to connect the speed pulse signal cable to the vehicle speed pulse signal terminal, which in my opinion is somewhere under the hood. I tried google with my car’s model and year but can’t find any info
Care to share? We’re not mind readers. :p
 

shortbus

Joined Sep 30, 2009
10,045
Also some of the more popular car models have forums dedicated to them. And many have schematics that won't cost you anything, but you usually have to join the forum to see them.
 

Tonyr1084

Joined Sep 24, 2015
7,899
Most Chiltons, Haynes or Clymers manuals have schematics in them.
I find that most don't have the pinouts for the dash wiring.

Some years back I bought a new truck. Speedometer was WAY off from actual speed. The speed sensor was located on the tail stock of the transmission. Knowing the proper tire size and the rear end ring & pinion gear helped determine the right driven gear for the sensor. Mine had a 29 tooth gear when it should have had a 30 tooth gear. Someone at some point put smaller tires on the truck before I owned it.

While not knowing the exact problem I did some investigation. I pulled the dash out and temporarily soldered a wire onto the connector pin that came from the speed sensor. Hooked up my oscilloscope and saw a nice square wave. I looked into those programmers that can change the speed calibrations but they were way more expensive than I cared to purchase. As for the schematic for my dash, I went to the dealership and asked if they could provide me with the necessary pages and they were more than happy to print them out. Once I knew everything was working properly I then turned to investigating the proper gearing for my speed sensor. Was then that I bought the proper gear. My speedometer is spot on at 50 MPH. At 25 MPH my actual speed is 26 MPH but at 75 MPH my actual speed is 74 MPH. Couldn't ask for much more accuracy.
 
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