Speedometer Needle Jumps [Archive] - GrandAmGT.com Forum


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06-25-2010, 09:21 AM
When i am between 0 and 50 mph and i am driving my speedometer needle will bounce back and forth. It will go down to 0 and bounce around to 10 and 20mph and then back up to the speed i am going. IT DOES THIS ALMOST EVERY TIME I HIT A BUMP IN THE ROAD.

Could this be dirty speed sensors? (wheel speed sensors) AND where are they located? Could it be a short in wiring? I feel like it is bad sensors due to getting road dust/dirt/oil on them and they are shorting out when i hit a bump.

If you have any personal suggestions, or dont want to post on here, please email me at jlnifong@gmail.com ---I need help her1, b/c it is making my transmission jumps sometimes! The tranny gets confused as to what speed the car is going!

06-25-2010, 10:19 AM
the speed sensors are built right into the wheel hub theres a wire that comes out of the back of the hub you can see it pretty easy sometimes if it comes off the little clip or someone does a crap install the wires can jiggle and over time break off at the hub. the wires are pretty thin.

06-25-2010, 12:26 PM
ok...i will check those wires...if it is not those wires, what else could it be? just a short somewhere? im just trying to narrow it down because it only happens when i hit a bump in the road?

06-25-2010, 12:39 PM
FYI - The vehicle speed sensor (used for speedometer/odometer) is in the transmission tail shaft. The sensors at the wheels are ABS sensors built into the hub and bearing assembly

check the sensor and the wiring to it and if that doesn't find your problem you may wanna check the wires under the dash from the dash to the BCM

06-25-2010, 12:46 PM
which sensors do you want me to check? the one near the tranny? or the wheel sensors? Thanks!

06-25-2010, 06:42 PM
tranny sensor, they're just abs sensors in the hub?

06-25-2010, 07:03 PM
yes, check the trans sensor as that is the one that has something to do with the speedometer working or not.

06-26-2010, 06:50 AM
isnt it on the right side of the tranny? under the car? do you just want me to check that and clean it? its just a wire and a plug in right? visible?

06-26-2010, 10:14 AM
haynes or chiltons go to an auto shop and "browse" the guide section or just drop 20$ on the book saved me a ton of money so far

06-26-2010, 12:11 PM
Here is a pic for a 03GAGT.
Hope it helps.