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View Full Version : RPM jump while using cruise control


Laine0318
06-30-2004, 10:36 PM
When I am going down the highway or an expressway with the cruise on, the tach will jump between 200-500 RPM's and hang for a few seconds and drop back down to normal. I noticed this about a year ago. At first I just thought that the car was adjusting for speed and hills and such. But I started to notice it on flat ground and when the RPM's would jump I wounldn't gain any speed.
There are days that it does it once or twice on my commute, and there are days where it will do it a couple of times in a mile. So I took it to the dealership and their answer for everything is to hook the computer up to it and it says no there is nothing wrong with the car. It really isn't a prob just more of an annoyance.
After the third time of taking it in I started to pay attention to when it would do it. On the expressway when I would go over and overpass when the pavement would change to concrete there is bump, then when the concrete would change back to pavement there is another bump. I would say 70% of the time it is on the second bump when it would jump. So I was thinking it may be a wheel sensor or I dunno. Anyone else notice this or heard of it or is my car a in a minority?



Chris

XtremeGrandAm
07-01-2004, 12:07 AM
Never happened to me could be a sesor thats messed up

ophidia
07-01-2004, 07:25 AM
maybe it had to throttle up a little because you were going up an incline, so the torque convertor unlocked, then locked again?

Laine0318
07-02-2004, 06:11 PM
9 times out of 10 is is on flat ground. I took it in a few times and the Dealership doesn't seem to know what to do. all they do is hook it up to the computer and it says nothing is wrong. So I dunno.


Chris

jayhawk
07-02-2004, 06:59 PM
Speed sensor is not communicating. Not the wheel sensor, but the sensor for the speedometer. Same thing happened in my 1997 GA. Nothing to worry about.

Laine0318
07-04-2004, 10:14 PM
Did you get it fixed or left it alone?


Chris

jayhawk
07-05-2004, 08:02 AM
Left it alone.

Texican
07-09-2004, 07:08 PM
Does it happen when the A/C is off?

Laine0318
07-15-2004, 09:41 PM
Does it with the AC on or off. I thought I would would try to turn on off the ETS but it still did it. How much does a speed sensor cost?