Need help in finding the correct wire (color) and location for the speedometer for my 2007 Equinox. Better yet, what I need is to be able to see or measure the difference in voltage change or timing as my speed increase or decreases. What I would like is to be able to add tap this information via a harness cable within the cab with very little damage to my car.

Thanks,

 

Speedometer info is sent thru lan bus on the new lan bus vehicles. Be carefull trying to tie into the wiring of the new lan bus system.

 

The only place to find this wire without the use of an aditional module would be under the hood at the Tranmission comtrol module. Specifically you will be tapping into the Output Shaft Speed Sensor(OSS). Basically a vehicle speed sensor. your looking for a red wire in pin #2 of connector 3. The TCM is located on the top of the tranny.

 

Just like with every other GM vehicle, the speedometer wire is the green/white wire that goes into the back of the dash cluster. It is NOT controlled by the CAN bus, but is controlled via the ECM from the transmission output shaft. If you're trying to tap into speed signal, you absolutely can use that wire. This can also be used for Navigation radio tracking as well. The tachometer is via the CAN bus using the signal from the crank position sensor.

You probably already figured this out, but that's the correct referrence for anyone else who might ask the same question.

Thank you.

 

Vehicle speed has been transmitted digitally to the cluster on most GM vehicles since the early 2000s. In the case of a 2007 Equinox, the only green/white wire coming from the cluster goes to the buttons used for toggling the DIC display so you definitely could not use it to acquire a vehicle speed signal.

Excerpt from GM's Service Information: "The TCM calculates vehicle speed based on the signal received from the Output Shaft Speed Sensor (OSS). The IPC receives the vehicle speed message from the TCM via serial data. The IPC displays the vehicle speed based on the information from the TCM."

 

don't follow the TCM. The digital lighting number wire is dark brown. Always has been since the 1980s. The speedometer wire is dark green and white. This is the only speedometer wire for any GM vehicle it has always been the only speedometer wire. It's the same wire used to connect to an external speedometer or for a navigation radio, and I've connected multiple radios with no issue. This wire is analog. This choir comes directly from the speed check into the firewall and then splits into multiple sections beyond the firewall. It goes to the speedometer problem and the body control module. Also has a runoff to the ABS module. This is how all DM vehicles have been wired since the 1980s 1990s 2000s and today. What you think is the digital part is the part that goes into the body control module, what's the body control module translates it into a signal down the GM land data bus for things like the radio and other features as in speed controlled volume. This is how this works. This is the way. Also if you are going off a Chilton's manual, it is 100% incorrect on the wiring diagrams.

 

No, we don't use door stops for service information here at the dealership. Below is a screenshot from GM's Service Information. This is a circuit list for the one connector going to the instrument panel cluster. As you can see, no analog speed signal goes to the cluster. You can't argue with information straight from the horse's mouth.