As many of you know, I don't speak Buick, but I'm learning.
I have a 1990 Electra Park Ave. It'* a half year so most things in the FSM aren't right. It'* not quite an 89, nor is it a 90, nor is it a 91, but some things are.

This morning about 7 minutes into my trip to work....


Alright.. so I pull into a gas station. Check the coolant level, everything is fine. I check the temp of the upper and lower radiator hoses, thats fine too. Check for leaks.. there are none. I even shut the car off and start it back up (a VW trick). nope. temp light still stays on. The radiator fans are both blowing hard too but there is cool air coming from them, not hot like if the car was over heating. Also it was about 76 degrees this morning so it wasn't hot out.
I baby it as I get on the highway and only go 70 (instead of my 75-80)
I get to work and the coolant level has gone down a little but not much so I leave it. I check everything again.. fans are still on full but blowing cool air, both hoses are warmer but not hot to the touch. HHmm weird..
So I go into work and don't think too much about it. I am driving home and the second I get on the highway the TEMP light comes back on again. It never flashed, it just stays on. So I am about 1/2 way through my trip still only going 70 (outside temp was 92.. was a cloudy day today and the wind was blowing hard.. one of those pre-storm winds)Then.. the temp light goes out and 2 seconds later...


Alright.. so still going 70 and with 2 miles left to go until I get on the city streets I am watching the cluster pretty often.. I get a cool light show now. The temp light comes on for about 5 minutes then the SES light comes on for about 2 minutes then goes back to the temp light.. but they never came on at the same time.
On the last road I drive on before I get on my street the SES light comes on and stays on (with no temp light)...


As you can tell, there is almost 76k on the car.

Ok now.. This is where I need the help. FSM says to short diagnostic pins A and B and the SES light will flash. My car doesn't have that option. There is only one pin on the diagnostic port and that'* pin M. I read somewhere that you're supposed to hold 2 buttons on the Climate control and it will flash codes but I can't get it to do it. There was a post on here for a 93 Bonnie that you are supposed to hold the ECC and WARM buttons, but that doesn't work on mine. I thought I remember reading in the FSM how to do this but all it says is short pins A and B.
I want to find out what the code is before I go changing things. Yes the coolant probably needs to be changed since I never did that in the year of owning the car (and if the coolant is just as nasty as that brake fluid was yeah.. time to change it!) I'm also thinking it might be time for a thermostat. It doesn't get too cold down here but the car HAS seen 31 degree weather a few times this past winter.. It'* a Zonie car, never even seen snow before.
So.. Can someone please tell me what the combination is on this climate control to read the codes? I'm just not feeling like giving the Buick stealership $85 to read a code and then tell me "we can't let you have the car back until we do a coolant flush and oh! that will be $200. I'm strapped for cash right now.
Thanks

The only codes you can pull from the climate control system is climate control error codes. What you will want to do, as you mentioned, is bridge 2 pins on the OBD1 port, under the dash on the drivers side. Codes will flash through the SES light, you count the flashes, you get the codes.

I have guesses, but I would like to hear what codes you get

I wish I could, but like I mentioned, I only have 1 pin and that'* a data pin, well, that'* what the FSM says anyway. I've crawled under there and there aren't any other pins.
Like I said, this is a weird car and I know the only way to get the codes are to do the combination things on the climate control (which I don't know) or take it to a stealership.

I got my answer this morning. 4 blocks from work it started to sound like rod knock. Yes, I got the OH ISH feeling in the pit of my stomach, and had to stop at a light. Steam was coming out all over. Turned into the driveway to work and the engine died. Started it back up and got it pulled into the parking space and turned it off. Opened the hood and I have coolant all over the place. No hoses were popped. Then, I look at the water pump and sure enough, coolant all over there. I'll be going out once the sun comes up to find out if I'm going to be doing a head gasket job as well.