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How do you check the codes on a '89?

AJMBLAZER

AJMBLAZER

Better to be lucky than good.
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Pulled out a paper clip and my Chilton's manual...


...only to discover it says I can't do it like I could on the OBD-I TBI gasser trucks.:doah:

So how do you check the codes? CEL light is on near constantly now and I'd like to know the problem.

Where's the plug?

Anybody know where I can get the tool/scanner?
 
infact, your truck shouldn't have a computer... Mechanically injected 6.2L, only things electronic include the glow plugs, fuel shut off solenoid, and the temp switch for the high idle / timing advance solenoids.

Where most gassers have a SES light, my diesels have always had a low coolant light. Might want to investigate incase someone changed your cluster out or something.
 
As stated above, the '89-'91 6.2 Blazers and Subs do have a computer and a check engine light. However it does have very limited controls....I think mainly it just monitors a few items but doesn't actually run anything. It's been years since I check the codes on my '90 but the old Snap-On diagnostic tool had the plug conversions to do it. Thinking the diagnostic plug was under the hood, and it's not powered so you had to run a seperate line to the battery for power. I'll try to look it up on AllData if I have time and see what it states.

Like I said, it's been years since I checked for codes and after researching it and finding out the computer didn't really do anything never bothered to look at them again (was thinking there is less than 10 codes).
 
Yeah, the Chilton's lists very few and really just says, "you can't jumper it and must use the correct reader."
 
I check mine with an my Genisys os Modis scan tool. I have never tried to check it with a paper clip. I didn't know you couldn't.
 
Not having much luck finding any of the tools or anything.

Guy on TDP said I could just yank the whole assembly. Might just yank the bulb from the thing and leave the computer and it's wiring alone.

Russel, just FYI here's a shot of where GM scabbed on the SES/CEL.

SES light.jpg
 
Heh, learn something new every day!

I wonder what the point of it is if it doesn't actually control anything?
 
It is for emissions monitoring kinda like the California cars with computers and carbs in the early 80s.
 
It's another feel good bit of stupidity like an EGR in a diesel.
 
AJMBLAZER said:
Not having much luck finding any of the tools or anything.

Guy on TDP said I could just yank the whole assembly. Might just yank the bulb from the thing and leave the computer and it's wiring alone.

Russel, just FYI here's a shot of where GM scabbed on the SES/CEL.
Click to expand...

Interesting....my '90 has the actual SES light in the gauge cluster, same place the gassers have it. That light doesn't look factory, but maybe for the '89s????
 
I'm hearing that's where they scabbed it on at the last moment when they realized "oh ****, this has to go somewhere."
 
Did you ever figure out how to read the code, or disable the Check Engine Light? I've got one lighting up on my 1990 6.2L Burb, and I need to take it in for inspection soon, so need to get the light out. (Visual inspection only, so as long as the light is not lit, it's fine)

On my Burb (all stock), it uses the factory "Service Engine Soon" light in the gauge cluster.

I guess worst case I could pull the gauge cluster so I can pull the bulb out of that light. But I don't want to do that (and potentially crack plastic in the process) if I don't have to! :crazy:
 
When I put the J-code intake on it pretty much came on permanently so when I put my new stereo in last October I just pushed the thing up behind the dash, pulled the bulb, and forgot about it.

I ought to just find the computer and pull all the stuff out but it doesn't do anything anyway...
 
thecarman said:
Did you ever figure out how to read the code, or disable the Check Engine Light? I've got one lighting up on my 1990 6.2L Burb, and I need to take it in for inspection soon, so need to get the light out. (Visual inspection only, so as long as the light is not lit, it's fine)

On my Burb (all stock), it uses the factory "Service Engine Soon" light in the gauge cluster.

I guess worst case I could pull the gauge cluster so I can pull the bulb out of that light. But I don't want to do that (and potentially crack plastic in the process) if I don't have to! :crazy:
Click to expand...

Problem with that is when they do a visual, it's supposed to come on for a few seconds then go off, otherwise they will know the bulb is out or burnt.
 
imiceman44 said:
Problem with that is when they do a visual, it's supposed to come on for a few seconds then go off, otherwise they will know the bulb is out or burnt.
Click to expand...

Good point. Luckily the place I get it inspected won't do this - they would just notice if the light was already on.

I do wish I could find the "real" way to read the code and stop the light from coming on, but I'll work around it if I have to, and I'm *not* taking it to the dealer to read it. :)
 
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