Speedo only works when brakes applied

[Junkster]

Any thoughts on why the speedometer and odometer will only read when the brakes are applied. Cruise control does not work either as the speedo only registers when you apply the brakes. the automatic door locks will not lock unless you apply the brakes to slow down doing more than 15 mph. the Tahoe is a 2001 5.3 liter 4x4 with 116,00 on the clock. I am thinking the speed sensor on the output shaft of the transfer case or could this be something else? The speedo never jumps or anything else that would make you think it was a servo .

 

[Junkster]

Update: I replaced the speed sensor and it is still doing the same thing. Speedometer and odometer only register if you apply the brake. You only have to depress the pedal enough to activate the brake switch to make the speedometer to start reading. I tried pulling the fuse to reset and tried again with no result change.

 

[samotahoe]

sounds like you might have a wiring, or guage issue my friend. see if you can find someone with a scanner to check the body control module. maybe you can find some type of code in there. if not a tech2 would work great also.

 

[Junkster]

Well had a buddy that works for GM take it to work and check it and he found issues with the Tach and Speedometer not scan properly I have take the cluster to Automotive Scientific Inc. for repair.. I will get it back at the first of the week so I will know if that fixes the issue. IF not I will be looking for an Electrical schematic to try and figure out what is going on .