Greek

Hello everybody,

I am new in your boards but I am really trying to keep up with all the info out there. Anyway I tried all kind of searches about SES and could not find anything relevant to my problem.
Here it goes: When I turn the key for the ignition all the way (without starting the engine) I get no SES light. Also when I use the paperclip (according to Vader's and GMTech's instructions) I still get nothing. I have the car for almost 2 years and I have never seen the SES light. Car runs pretty good (always needs a small tune-up) but without a light? The reason for this post is to find out if the SES light should come on when I turn the key.
I have a 1988 Pontiac Firebird Formula 5.0 V8 (305) LB9 MT.
Any help is appreciated. Sorry for the long post and thank you in advance.

Harry the Greek.

Blackened

Ummm.... either your SES bulb is burned out or someone removed it! I bet it's either one of those two

Z28DJP1987

I will second the previous Post. Remove the panel and check the bulb.

Greek

I removed the panel and checked the bulb (interchanged that bulb with the one from the seat-belt warning and the one from the shift-up light. It still doesn't work. Thanks anyway.

86z/92rs

Any of the other lights next to the SES lights work?

Greek

Everything else works.

Blackened

The bulb socket is probably messed up... or the wiring behind it.... orrrr the wire from the ECM that turns that bulb on might have a break in it, orrrrrrrrrrrrr the ECM driver that turns the bulb on is fryed in which case you might need a new ECM if want the light to work.

Greek

I am willing to try tracing where the problem first occurs. I obviously can not start from the bulb socket since logically this is the end. Any help on the steps that I should follow? Thanks again everybody who is helping me.

Vader

Greek,

Welcome Aboard!

Actually, you can start at the bulb and socket, since it would be half-splitting the circuit. (It isn't the end of the circuit in this case.)

The bulb receives 12VDC+ from the GAGE fuse in the panel whenever the ignition is turned on. The ground for the lamp is controlled through the ECM, just like most other ECM loads. Make sure the lamp has 12V+ when the ignition is on. If not, trace back to the fuse. If so, check the ECM grounds, wiring to terminal A5 at the ECM and wiring at the ALDL socket.



In the interim, you can test the "SES" lamp (MIL) operation right at the ALDL with a test lamp. The 'D' terminal is the ground for the MIL, and you can connect a lamp to a 12V+ source and ground it at the 'D' terminal to perform the same functions as the MIL on the dash panel.

Greek

Thanks Vader, I will let you know.

Later,

Harry

Greek

Vader,

I tried to do the above. Guess what. The 'D' terminal has no connector inside (the same thing is true for H, J, K, L too on the bottom half and maybe one more on the top part - I don't remember).

Now what? Sorry to bother you all like that but I am confused.

Thanks,

Harry

Vader

Greek,

That IS odd. An '88 should have a nearly full compliment of connectors - especially and LB9 due to the fuel injection. I could understand the lack of connections in the H, J, K, and L terminals, but the rest should be full.

Has this car been rewired?

Greek

Nope. Atleast as far as I know. Anyway I asked the first owner (brother of a friend) and he said no. They just changed the ECM at one point with exactly the same part number.

Thanks again,

Harry

Greek

Vader,

I just checked the ALDL again. Besides D, H, J, K, and L terminals eveything else is there.
Also I disconnected what I think is my ECM (correct me if I am wrong). It is a black box on the passenger side with a connector on one side. You said at one point that this connector has a fuse or fusible link somewhere. Where is it?
The numbers from my "ECM" are:
25075044 B
37DA

AC

Is there another way to test the ECM directly? You said "If so, check the ECM grounds, wiring to terminal A5 at the ECM and wiring at the ALDL socket." How do I know which one the A5 is?

Thanks again for all the info and the help,

Harry

Vader

Greek,

It's good to hear that most of the ALDL terminals are present. Look closely at the 'D' terminal to make sure the connecor hasn't been pushed back out of place. You could also look at the back side of the connector with a small mirror to see if the brown/white wire is even present. It should be connected to the 'D' terminal on your ALDL. This wire should also be present at terminal 'A5" at the ECM and continue to the "SES" or MIL lamp on your instrument cluster. If the wire is there, it is the ground for the dash lamp or your test lamp. If the wire is not there, it should have been at one time, and you'll need to go to the ECM connectors to find it.

Your ECM case should be bare aluminum, not black-colored. The part number on the ECM should be 1227165, and there should be two connectors on one end of it.

The part number you provided is for the 4 output buffer module, and the box may also be yellow. It is attached to the back side of the ECM. That black mounting plate you see the module mounted to is the bracket that holds the ECM. Remove the two screws on the bottom edge of the bracket and the ECM should lower out of the dash. There is a guide pin molded into the upper edge of the bracket to locate it at the top side. The entire assembly should look like this:




Before you get too deep into the ECM, you can still perform a couple of tests without a working MIL lamp. As long as you have the 'A' and 'B' terminals in place, jump the two terminals and turn the ignition to RUN without starting the engine. If the electric cooling fan starts, the ECM is reacting normally. We can already assume the ECM is working, since the fuel pump realy operates and the engine runs, but this would just be another I/O and mode test.

Your ECM is probably O.K., or at least not totally dead, or the engine wouldn't run at all. The ECM controls all fuel injector pulses, and therefore all fuel flow.

Greek

Vader, YOU are good. YOU!!! (This is a quote from Analyze This with Robert De Niro).

Anyway,

I opened up the kick panel (because the module that I described before is located higher behind the Performance Suspension logo) and I found the ECM (aluminum) and the yellow output buffer module. I took a close look at the cables and the brown/white wire is "cut". It looks like it has been cut with a cutter and not by accident. Anyway I connected it and now the SES light comes up.
When I turn the ignition to RUN it blinks once. (Test probably).
When I turn on the engine SES turns off immediately.
Also now the paperclip trick seems to work although the only code that I get is x,xx (I think this is 12 when flashes once and then twice). I get that code for ever - it never stops (or at least not for 7 times).
Anyway Vader I know that you are writing a book. Is there a lesson on SES that you can forward to me or tell me where to look? I am interested in how SES works when driving, testing or in general. Also the codes would be helpful too.

Finally thank you again for all your help so far,
and I am sure you will hear from me again.

Also check your email.

Later,

Harry the Greek

Synapsis

Greek - The code 12 you're getting is the ECM telling you that it's working properly.

Here's where I got my initial information about the SES trouble codes when I first got my car, hope it helps you.

http://chevythunder.com/fuel%20injec...g%20pg%20a.htm

Welcome to the site. =)