ECU code help

[Zetto*]

So the check engine light on my 1990 240sx fastback came on recently. I pulled out my ECU and from what I can tell it's spitting out a 45. Here is my text interpretation of what I get. It flashes twice, Then three times, Then four, Then five. I'm assuming that's 45 which is supposed to be an injector leak (According to my uber ECU book) but I checked and none of the injectors are leaking. So I figured what the heck and pulled off the negative battery cable to reset it. When I reconnected the cable and started the car the check engine light was on. I checked the ECU once again and got the same codes. Any help on this would be very much appreciated.

[SJDrifter]

same here xcept i also get 32 wich is EGR Function... i gave up on it...

does your car smell really bad outside?

[Nuisance Crew]

hmmm, there is no 23 code, are you sure you aren't just looking at the light cycling through the modes? when you turn the screw clockwise it will give you 5 diagnostic modes, you want number 3, so:

1. turn key to on position (don't start engine)
2: turn screw fully clockwise, after it flashes the 3 times in a row, turn it back fully.
3 you are now in daignostic mode 3 which will list off the codes one at time, if your ecu is like mine, then it has a red and a green led, the red is the tens, the green is the ones so a code 12 (maf sensor) would be 1 red flash and 2 green. if there are no codes stored it will give you a code 55.
4. to keep codes stored, turn car on. or...
5. to erase codes, turn screw fully clockwise again, it will flash four times for mode 4, turn back fully. then turn key to off. entering mode 4 after being in mode 3 will reset codes.

sorry if you know all this already, hope this helps!
JD

[EchoOfSilence]

yeah, i'm gonna assume you didn't turn the dial back when it flashed that it was in Mode III.

listen to nuisance.

[Zetto*]

You guys are right I was forgetting to turn it back. :smash:

Interestingly enough for no reason my check engine light went out. Since the code should still be stored I will check it again later.

[imrickjamesbich]

theres 4 modes for the sohc??? the dohc only has 2 modes. weird

[Zetto*]

Either I did it right the first time I'm crazy. After doing it step by step the way you guys stated I still pulled a "45". I decided to clear the memory and proceed to drive it. The light has yet to come on so we shall see what happens.

[Nuisance Crew]

could just be coincidence about the 45 and the 2,3,4,5. Yeah, i guess just see if the code pops up again.