Check Engine Light CEL reset on 400E

[PDX]

Let me start by saying thank you for this wonderful resource, it is truly irreplaceable.

I've searched the forum a bit, but quickly got lost in the details of pins, and codes, and readers.

I have a 92 400E, USA model, 150K miles, with ASR and ABS. When I start the car in the morning, no CEL, but as soon as I shift into gear, the CEL comes on and stays on. It seems to reset itself overnight. The CEL behavior is new, and started around the same time I was dealing with the "soggy distributor cap" issue. Car runs great now that I dried out the distributor caps etc., but I keep getting the CEL, which is more annoying than harmful.

I am wondering if the simple "homebrew" light would be sufficient for figuring out why the CEL keeps coming on? I am capable of building the homebrew light if that is the direction I need to go. I also read about a built in light/button on the outside of the CAN (?) box which might be used to reset the CEL?

I'm new to checking codes, and apologize if these are dumb questions.

Again, thank you for this wonderful resource.
Cheers,
-Mike in Portland

 

[gsxr]

Mike, that does not sound normal. First thing I would do is pull the instrument cluster and make SURE that the bulbs are in the correct order. Sounds to me like the wrong bulb is in the CEL socket (position #1)...

 

[Stevester 500E]

What's the easiest way to force-trigger a CEL?
I have a DM code 4 but no CEL light came on.

I thought a DM code 4 triggered a CEL?
The light bulb is fine as all cluster lights turn on right before starting the car.

 

[gsxr]

Yes, code 4 will trigger a CEL (BT,DT). Disconnecting the IAT behind the driver headlight should also trigger the CEL, and store code #9 on the DM.

Keep in mind that the CEL does not necessarily trigger immediately. It may take several engine starts, with X minutes of driving after each start, before the DM triggers the CEL on the dash. I don't know the exact timing but I think at least a half-dozen starts over an hour or two should suffice? If you think the DM is bad, swap it out, they are cheap since they are relatively rare failures.