I have a 2004 Pontiac Sunfire, and this morning the speedometer stopped working properly. When I am completely stopped it now reads 25mph. All other gauges work fine. For the past 2 weeks the needle on the speedometer has been sticking. For example if I was going 60 and accelerated to 70 instead of the needle accelerating with me it would jump from 60 to 70. Do I need to replace the instrument cluster or could this be a problem with the speed sensor? If I have to replce the cluster looks like that the entire dash needs to be removed to get to the cluster. (I only took a quick glance.) Is this correct, or are there screws that I am missing to where the driver's side can be removed for easy access?

Quote:

---

Originally Posted by shelley7180

I have a 2004 Pontiac Sunfire, and this morning the speedometer stopped working properly. When I am completely stopped it now reads 25mph. All other gauges work fine. For the past 2 weeks the needle on the speedometer has been sticking. For example if I was going 60 and accelerated to 70 instead of the needle accelerating with me it would jump from 60 to 70. Do I need to replace the instrument cluster or could this be a porblem with the speed sensor? If I have to replce the cluster looks like that the entire dash needs to be removed to get to the cluster. (I only took a quick glance.) Is this correct, or are there screws that I am missing to where the driver's side can be removed for easy access?

---

In most cases the problem is in the cluster. And yes, the instrument panel upper pad has to come out first, not the whole dash.
Attachment 5475

Lots and lots of hidden screws, so pull gently until you're sure it's loose!
Don't drop anything down the defroster duct!

Attachment 5474

I meant to include this in my initial question, but I forgot. When I buy a new or used cluster how do I get the mileage to read correctly? Is there a way I can reset it myself, or should I have the dealership do that? Even if I can do it myself is it better to have a mechanic do it so I have a receipt of the repair for when I trade it in?

If you have the dealer do the entire repair, they will send your instrument cluster out for repair, or order a replacement based on your current odometer reading, and then reinstall it with the same mileage. Ordering locally here takes about three to five days turnaround.
I am glad that you considered what many don't.

I found a great site to report any problems with your car that compiles data to see if safety recalls need to be issued. If you go to Home | National Highway Traffic Safety Administration(NHTSA) | U.S. Department of Transportation. I had this same problem with my car that just started and I have no clue what is even causing it.

I have a 2003 automatic sunfire and my speedometer is doing the same as the last person only that added to this problem my car isn't changing gears at the right times and sometimes if I'm going 50 or 60 and I let off the gas she goes back into first gear. I'm thinking its my speed sensor?

Quote:

---

Originally Posted by parsnips

I have a 2003 automatic sunfire and my speedometer is doing the same as the last person only that added to this problem my car isn't changing gears at the right times and sometimes if i'm goin 50 or 60 and i let off the gas she goes back into first gear. I'm thinking its my speed sensor?

---

Whoa!

Shifts back to first?? At highway speed??
You have an entirely different problem. Maybe two problems.

The original post had a problem with only the instrument cluster displaying the speedometer incorrectly.

Your problem may be a transmission problem or with the Engine Control Module (ECM).
Are you getting a check engine light? If so, we'lll need to know what codes are being stored. Get back to us soon or you could hurt your transmission with radical shifting problems like you've described.

Not highway speeds its usually bettween 40km and 60km at it happens when I let off the gas if I keep on the gas she is somewhat OK and on the highway she isn't to bad she will get jumpy it seems as though that she does what the speedometer does when it starts going nuts its like the car don't know what gear to be in

Quote:

---

Originally Posted by parsnips

not highway speeds its usually bettween 40km and 60km at it happens when i let off the gas if i keep on the gas she is somewhat ok and on the highway she isn't to bad she will get jumpy it seems as though that she does what the speedometer does when it starts goin nuts its like the car don't know what gear to be in

---

Use punctuation marks.

I read on another forum that the mileage is stored in the computer not the instrument cluster, so dealer assistance is not required as the true mileage will be shown automatically. Anyone know if this is true?

rubrboots, I have never seen that. If that's true, control may be lost when the ECM fails and has to be replaced.

Not true.
The "computer" involved is only slightly more than a chip, attached to the cluster. While some data is maintained within the ECM, only the chip on the cluster can control the display.

I didn't think that sounded right, thanks for confirming it false. If I were to replace my cluster with a used one, would the dealer be able to correct the mileage difference?

Quote:

---

Originally Posted by CaptainRich

Not true.
The "computer" involved is only slightly more than a chip, attached to the cluster. While some data is maintained within the ECM, only the chip on the cluster can control the display.

---

That being said, I got a replacement cluster from a scrap yard to put in since my Tachometer/Speedometer were pegged. I put in the new cluster and the odometer is blank (no ERROR, no 0, nothing). I know it is still working because when I put in the busted cluster it immediately shows everything correctly. Is there a way to reset it? The car I pulled it from was about 1,500 miles over the actual mileage (searched a long time to prevent any potential tampering issues). Thanks a million. This forum is a GREAT help!