ECU Troubleshooting Help (90' Hatch)

[keeshimself]

Hi,

I tried searching this but it was in vain..

I just bought my first 240 a couple days back and I'm having some issues troubleshooting my ECU.

The car is a '90 240sx hatch with a '97 KA in it. As far as I know I still have a '90 ECU, correct? Which means the codes are projected from the ECU itself rather than the Cluster?

I read the guide to reading the trouble codes on a SOHC and it mentions a red light and a green light on my ECU but it doesn't go into detail of the location of the green one, which makes me think it should be close to the red one..When I turn my key for all the lights to come on I only see a Red light.


I guess my question is:

Is it the red light or the green light that flashes the codes? Or both? Or am I supposed to be reading the codes off the cluster? In which case the slot where the check engine light is supposed to be won't light up, even with good bulbs.

Any input would be great. Feel free to move this if I put it in the wrong sections.

Cheers,
K.E.

[keeshimself]

Update:

Upon further inspection, it looks like there is a spot for a green light right next to the red one but there is no bulb.

One of the screws on the front casing of my ECU is stripped...

Any suggestions on how to proceed from here?

-K.E.

[compactfean]

Its the red bulb that gives codes, I thought my screw was stripped too but I was using the wrong Phillips. You need a really small one. Go from all the way counterclockwise to clockwise for 2 seconds and back counterclockwise for it to start flashing codes.

[keeshimself]

which means I still have the 90 ECU?

[compactfean]

Yes that is correct ...which leads me to believe that if the harness is an s14 harness you need to check and see if the pinouts for s13 and 14 are the same....that might be your problem.

[SoCal-S13]

97's were obdII. so having a 90 ecu isnt possible. unless you have the conversion harness... take pictures of ur s*** and post em

[keeshimself]

I'll have to get some pictures up in the morning.

I didn't think there was much of a difference between OBDI and OBD II harness'. Either way,
there are a few sensors that aren't plugged in throughout.

-Kees