CEL comes on after 4-5 mins off a cold start. Found instructions for reading this vehicles OBD-I codes.

- Lift small cover to part 126 545 9740 just to right of battery
- Turn Ign. switch to 1st position - dash lights on
- Depress stalk type button on 126 545 9740 and hold for 3-4 seconds. Release and count blinks from LED light.

There is no LED light. I see 8 ports under the cover once lifted. Thought perhaps I'd have to read blinks from an LED on dash as some OBD-I vehicles work this way. Did not see anything going on there.

Any idea where this LED is located?


Update - Guess I needed to dig a bit more first. Turns out not all M103s have an LED. The following URL shows a homemade light used to diagnose an SRS issue. That is port 6. CIS(what I suspect is my problem) is port 3. The layout in this document lines up with my 8 pin setup. I'll make this gadget and report back my findings. MBDoc reported that most often CEL on this car is O2 Sensor. I want to verify and I need a way to reset code once fixed. Might be awhile as this is a non-critical issue at this point. Car not being driven right now.


http://home.comcast.net/~chwilka/Error_Code%20_reader_reset_tool.htm
Thanks.