90 C2, Check Engine Light, How do I check it?
 

As the title states, 90 C2 with a check engine light. I searched the forums and the internet and could only find a method for 91 and newer. Does anyone know a method to check this, or am I going to have to buy a code reader?

Hi,
You can't buy a reader for that car (unless you're willing to spend about $1000)
The easy route is to take it to the specialist garage and they should have the reader.
Or just unplug the battery for about 1/2 hour and voila! All codes will be removed.
It happened to me when I had a faulty O2 sensor, once replaced everything is perfect.
Ideally get the code prior deleting it.


good luck!

Durametric makes a scanner for our cars but it does have limitations. Also there are a lot of us with home made scantool's.

If there is a way to make a home made scan tool, please link me if possible!

I removed the lead on my battery in order to reset the code. I left the battery cable disconnected for 3 hours. Put the lead back on, code came right back! What code does not reset? I'm thinking faulty O2 sensor.

Could be many things... You need the scan tool. Here's the mother of all scantool threads.
Diag interface & Software - Rennlist Discussion Forums

Bill Wagner on Rennlist wrote up this article about displaying CEL codes as flashing sequences of the CEL light. It has worked for me to diagnose an injector failure. Plus, it's FREE!

http://members.rennlist.com/billwagner/CheckEngine.html

Will this work? Does it say 964's sold in 1991 and later which seems to me 1991 and newer cars?