97 Buick Lesabre speedometer works occasioinally.

[kwinaa]

My speedometer works intermittently and then it is inaccurate...what are the possible problems and would I have to remove the inst. panel? Help..
Thanks...Kwinaa

[Loekee75]

More than likely your speed sensor acting up. No need to remove the instrument panel, the sensor is attached to the transmission.

[vrmlbasic]

Would there be an error code thrown if the speed sensor was that messed up? I have a similar problem, though my speedometer always "works", it is never accurate.

From 0-50 (actual vehicle speed), the spedometer reads faster by 10 mph

From 60+ (AVS), the spedometer reads faster by ~20 mph.

Would this be caused by the VSS, or is it just one of my many out of whack components screwing something else up?

[Smith1000]

I have 2 '97 Lesabres and have replaced the speedometers (instument panels) in both. I put in salvaged units both times and one of the salvaged units was bad when I received it. I exchanged it at the salvage yard for another and have had no problems since.

My speedometer would read 20 mph at idle, sitting at stop lights. When accelerating, it would jump to 55 to 65 mph. It would then jump back down to 0 or 20 mph. It was all over the place. The tach would also act up. It would jump or tick steadily when cruising. The odometers in mine always worked fine though. The odometers continued to log the miles as if nothing was wrong. Is your odometer working? If it is, your vehicle speed sensor is probably working okay. If that is the case, I would lean to a malfunctioning speedometer in the dash. If the odometer is stopping as well, I might suspect the vss first.

When replaceing the speedometer, the whole instrument cluster unit is replaced (gas gauge, tach, oil pressure,etc.) It all comes out together. It just presses into the wiring harness and a few screws hold the whole thing in place. The dash plastic must come off to get to it. The trickiest part is reattaching the little shift lever cable to the steering column that allows it to read Park, Neutral, Drive, etc.

[Loekee75]

I believe P0500 would be the code you're looking for if you're speed sensor is faulty; have the ECM scanned at auto zone or O'Reilly auto parts, it's a free service. The scanner will read the description of the trouble code(s) should any be present.