First thank you Arthur,Suginami and the others for your postings on code retrieval and there meanings.
My problem now is I can never get the LED light to blink a one to tell me no faults found. I have held the button with a watch to time it for 2,2.5,3,3.5,4,4.5,5,5.5 and six seconds and the LED light never blinks at all.
The ignition is on and the car is not running.
Any idea what I'm doing wrong?
Thanks;
Paul

Try it with the motor running. You are testing the DM (diagnostic module) and I would use a scanner. It seems there was something weird about the 94-95 impulse system.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

A single flash indicating no code stored on DM of 94/95 OBD1 systems will not appear until the car has gone through ALL self test . This requires several
full drive cycles to test each Emmissions circuit/system. I have seen some take 2 weeks before completion.
The other modules, however, will bring up the single clear code as soon as the stored codes are erased and memory is reset.

Thank you Stevebfl;
I'll try it with the motor running and you are right the DM does act weird.
I wish,I had a scanner.
Thanks;
Paul

Thanks Arthur;
I didn't know it could take that long.
Thank you for your reply.
Paul

I have worked on these quite a while and I do think that the reasoning behind this design is so that the codes could not simply be cleared before one went for an emmission testing in some states . Notice that these with the DM [N59 module] are Cal vs Fed systems.
If there has been a CE lamp trip, they want it to be verified as Fixed rather than just cleared , I suppose.
It took me quite a while working with these and monitoring when the single would finally show up before coming up with this conclusion, but then I did find a couple of mentions of it from different data and it seems to confirm it..
{ All-Data has a piece on it ]
The other modules do not need this protection as they are simple fault diagnosis for other modules , whereas the CE is indicator to both owner and Inspector that Emmissions faults have been detected.
These OBD1 systems were in the transitional period to OBD2 and that is why they are capable of both Flash and digital readouts .
I have also tried a MT2500 scanner on pin 3 [same as built-in led. DM] and found same results.. you simply have to wait for reguired drive cycles/self test of ECU of Emmissions system ..
One good thing about the scanner over the flash is the modules on these do have the capacity to monitor misfires and injectors individually, etc .

Thank you Arthur for your reply.
It makes sense to me I'll just drive it for awhile and check it again.
I tried with the car running and it didn't blink then either.
Thanks;
Paul