So a few days ago I posted that my check engine light and brake light and ABS light all came on. Many suggested that a bad battery charge could be to blame so I went for a nice long drive and the next day when I started it up, the lights were gone so I figured that was that.

Today, the lights came back on, along with the stability control failure warning. Also the speedometer stopped working. Car is operating fine though. In a hope to maybe clear it, and start over I unplugged the battery. After doing that, I still have the same lights with a new warning of incorrect part fitted.

Any help would be greatly appreciated. Thanks in advance guys.

 

It sounds more like a battery/charging issue with that result. I would have the battery load tested and the alternator checked next.

 

Would be worth getting the stored code(s) as this will narrow down the nature of the problem but ................. my guess would be possibly P1638 and/or P1642.
These are CAN (network) issues and probably still down to the battery. The computers (modules) on these cars are incredibly voltage sensitive and although most of the mechanical stuff (starter motor, relays, fans etc) seem quite happy with anything around 12 volts, the electronics are very fussy sometimes to within one tenth of a volt.
+1 on RJ237's advice, but if the battery is more than a few years old, a new one might be a wise investment.
Not sure where you are geographically - here in the UK getting codes read can be quite expensive, whereas it seems to be a "no charge" service at many places in the US.

 

With the speedometer and ABS problems I'd also look at the wheel speed sensors and cabling.

Dave

 

This usually indicates a key control module (in this case, likely the ABS module) is not responding to or broadcasting the expected messages on the CAN bus. Early cars had power connections coming undone on the board itself (inside the module enclosure), and were quite easily fixed with soldering. Some folks choose to have them rebuilt instead. Once sure the battery is OK, it might be best to find a place that can read all of the computer codes, especially from the ABS module at this point, and post them here.

Better help would come with better details. New members are strongly encouraged to take a minute and update their signature with the details of their car...