Maybe a stupid question bt neds to be asked

[sjrose247]

I have a 1993 240 sx and have had trouble with it starting refer to zer...-help for the entire story

it still has the KA24DE in it and was wondering if the Check engine light on yours stays on when you turn the key on engine off

the reason i ask is i have checked the powers and grounds for the ECM and have found that it has both, all the ignition and fuel components check out according to the FSM and the trouble trees in it. and have been looking at the ECM as a possible cause

The FSM states "Diagnostic test mode 1: in this mode the red L.E.D. and the MIL in the instrument panel stay "ON" if either remain "OFF" check the blub in the MIL or the red L.E.D.... [crappy Cali model information]... MIL and red L.E.D. : "ON" when the ECM C.P.U. or CKP sensor is malfuctioning---"OFF": O.K."Reference Page 41 in the EF-EC section

when i check the codes it flashes a 55 which is "No malfunction" however if i am in the blub check mode the check engine light stays on and will not turn off. so i was wondering according to what the FSM is saying (if i am reading it correctly) that if the light stays on i have a problem in the ECM in one way shape or form, which could be a blown ECM...

Bottom line can someone run out and check see if their MIL stays on or if it doesnt or can correct my thinking on this matter THANKS!!

[Wc240]

when your key is in on position(KOEO, key on engine off) your CEL, among other lights, should light up. when you start your car(KOER, key on engine running) your CEL light should go off. (that is the standard bulb check even for california smog)

[sjrose247]

well what im asking is if you have KOEO (key on engine off) and wait, most vehicles do a bulb test which typically the MIL, brake, ABS etc tur on for several seconds then tur off thats the bulb check the PCM makes and my understanding is that is diagnositc test mode 1, test mode 2 is self- diagnostics (codes), test mode 3 is O2 sensor diagnostics. at least that is how i know it, but i dont have much experience with nissan and how it does things, and since OBD1 is not a universal system like OBD2 is Nissan could have a flashing rainbow as thier bulb check and it still would have passed for the laws at the time.

If someoe has an S13 with a KA if they coud just go out to thier car turn the key on engine off and wait like 10 seconds or so and see if the check engine light turns off after a short time and say "yes the bulb stays on normally" or "no the bulb doesnt stay on normally" is all im asking

Thank you

[Wc240]

sorry, thoght i answerd that. yes, it(mine and every other 240/nissan ive worked on) will stay on all day in that position until you turn to another psition, i.e. run or off. if you look into the fsm, itll say what the modes are. i dont know off hand, mines 89 and its1 exhoust gas sensor monitor2 mixture ratio feedback control3 self diag system4 switches on/off system5 real time diag.id say to downlad an fsm for your car so you can have that info on hand, but yes,your cel light is acting right.

[sjrose247]

ok well let me make sure we are on the same page im talking abotu the key in the RUN position meaning if my car DID start you turn the key to get it to turn over then it starts you let go and its in that position vs the accessory position. Right? and in the run position the check engine light goes on then turns off after a few seconds. thats how i interpreted the FSM

i quoted it word for word in the original post if you have a different manual

[Wc240]

koeo,engine light on, koer, engine light off, after a few seconds.not good with enterpreting online either,so dont feel bad. but it sounds like you got the idea. after your engine is running, your light should go off. its when your driving around and your light stays on, that its a problem. got it? if not, say so and ill help you out