A CE lamp is not diagnostics for the cars systems..it is simply a warning that the N/59 emmissions module has detected a fault that will effect the emmissions mandates of a Cal car.
And the purpose of the CAN wireing is that it allows modules info to interchange/communicate with one another ...that's all...those codes get monitored by the N/59 module, as many originate and are from the other modules. But they will only trigger a CE via N/59 if the fault will effect the emmissions...it it does not, then N/59 does not trigger CE to ground for ilumination.
A simple example of this would be a triggered CE lamp and the code fault that triggered the CE fault could be found in the DM N/59 module via the built-in Led/Sw...but that might just say " Ignition Fault". [ code 7] ..b/c an ign. fault would , in fact, effect emmissions mandates...but if you then went to the IGNITION MODULE -pin 8, [ which is where the fault originated and CAN sent it to N/59 in the first place] .. that would tell you a specific ignition system fault...like a particular coil that has a low output, etc. [ code 23, for instance].......The offending failure is that coil and it is detected by the Ignition module first, not the emmissions module...but the emmissions module knows thru CAN that an ign fault has been detected by N-3/4 and that fault is going to effect the cars emmissions ...so it triggers the CE...and when you go for a test, the guy sees a CE and he knows your car has a fault that will not allow it to pass an E Test..but the fault can be from another module and the true code is not in the N/59 module..it is in an Engine Management module. In this example , in the HFM/SFI -N3/4 module..which is accessed at pin 8 on the 16 pin, Black Box diagnostics connector next to the battery. The N/59 will simply direct one to the Ignition module for further. more refined Ignition System diagnosis.......
The thick of it is there can be stored codes in the Engine management modules w/o a CE lamp b/c a CE is an Emmissions related code, not an Engine mangement or running gear code. Another example of such is you could have a detected intermittant bad stop lamp sw. contacts screwing up your ASR system and you will see a code 5 in the EA/CC module at pin 14, but that would never be detected by, or trigger, a CE lamp.
The real codes are in those other modules and that is why I told you to check [ pins 8 and 14] for your conditions. That is why there are many different pins..they each go into the memory of the different systems modules to look for codes in THAT module.
A car from Fl can have Cal emmissions , Fax or no fax.. Cal E only means that the car is cabable and set-up to pass Cal Es...which they all went to in subsequent years ..most all 94/95 OBD1 are Cal E with CE lamp and N/59 module..your years was option..Fed or Cal b/c that is when they were making the change.
This may help you understand better than my explanation:
http://www.peachparts.com/shopforum/showthread.php?t=107630
After '95, they were all OBD2 and the code dianostics were refined and digital...way better and more specilfic.. but the Flash codes of OBD1 were a start and there is owner accessed info in there to aid you in systems diagnostics. And for $10, you can build your own code retrieve Led/Sw combo that will get you the codes from the other pins...not bad info to have avilable with simple owner access.............this same tool can also be owner used for simple Ce lamp deactivation/code clear, and Module Memory reset procedures...............................................