420 SEL - Check Engine Light Codes Needed.
 

Having repeated problems with a check engine light coming on, and not being resolved by my mechanic.

So I have two questions:

1) Does anyone have the check engine light diagnostic codes for a 1991 420 SEL? (Codes given for other models, but not the 420).


2) On the 91' 420 SEL, does the checking of the codes require special diagnostic tools to check or, like I've read in other posts, is there a LED light flash that can be counted? If so, where do I find the LED?

Thanks in advance for any info.

(And this a great forum, not sure what I'd do without it...)

LED/Sw combo should
 

be located near the F23 box. Mine is attached to the side of it.

Now you say, where's the F23 box? It can be found on my page, click menu #2. It's officially called the X11/21sw.

Although some of the codes are not the same as yours, most are! So read through the menus.

Remember that reading the codes from the LED/SW combo, are just for the Diag Module, but those should give you a feel for what's wrong.