91 200 TQ Wagon stalling

Phil Rose pjrose at frontiernet.net
Sat Jun 19 19:10:04 EDT 2004

At 3:46 PM -0600 6/19/04, Watts wrote:
>  my "check engine " light is now on.
>Is this light emissions related?

Actually, many (most) '91 200q cars do not have this particular 
(check engine) lightbulb installed, but yours obviously does have the 
bulb, and that's a good thing, as Martha would say.

>  Should I park the car? Don't know how
>serious this light is.

No, don't worry that you need to "park the car" to avoid serious 
damage.  But you do want to find out what caused the warning. 
Possibly it's related to your stalling problem. This light is just 
telling you that the ECU (engine control unit) has detected a "fault" 
of one sort or another--related to one (or more) of the dozens of 
sensors and electrical gadgets trying to run your car.  Each "fault" 
is identifiable by its unique "fault code" number that is stored by 
the ECU whenever a fault has been detected.

In fact, your "check engine" light serves a dual purpose. One is to 
simply alert you to the fact that something wrong has been detected, 
and a second function is to actually help you identify the fault by 
means of a "blink code".
There is a set of (three) diagnostic ports/terminals located in the 
driver's footwell area-- just above the brake/clutch pedals. Using an 
ordinary length of wire conductor (or paper clip), it's possible to 
momentarily bridge a pair of these ports to initiate a repetitive 
series of "blinks" from that check-engine light. You count the number 
of blinks to arrive at the code number(s). It's easier to do than to 
describe, and it's all plainly laid out in Scott Mockry's fabulous 
web site:

and here's the complete list of code #s and the meanings:

A good idea is eventually to install a simple momentary-on miniature 
pushbutton switch (wired permanently across the appropriate pair of 
diagnostic terminals). Then you can reach down, push the button and 
read the blink codes without going into contortions with your head 
stuck in the footwell.

Or, you can go to a dealer/repair shop, who can attach a special VAG 
tool to those same diagnostic ports and read the codes directly. Of 
course expect to pay the prevailing shop rate for this 
service--probably 0.5 hr minimum.


Phil Rose
Rochester, NY
mailto:pjrose at frontiernet.net

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