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So…let’s cut to the chase. Finally got some decent weather to work on car outside. Pulled codes 42, 12, and 31. This was done on my little crappy $20 buck code reader. I’m pretty sure of the number of flashes; I went through the sequence 5 times, and there was no change. I counted the first flash as a long flash, and the second flash short.
I guess this is a pre-OBD 2 setup. I can’t figure out how to enter these codes in the database to see what they mean. The car seems to run fairly well, but then there are times when it misfires and coughs, stumbles etc.
Any old timers out there who can point me in the right direction? I hope it is a cheap direction. (Ha Haa)
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DTC – 42 Ignition bypass circuit error
DTC – 12 No distributor reference pulse (diagnostic test active)/passed test
DTC – 31 Wastegate solenoid circuit errorGoogle those my friend. Mind you though, obd-i sometimes had a few meanings for the same code depending on vehicle.
ODB II was not mandated by law in the United States until Model Year 1996… Some 1995’s had it, but was not required…
ODB I codes varied by manufacturer as stated… Try this link about GM…
http://www.gmtuners.com/OBD1_DTC.htm
-Karl
12 – Starting diagnosis
31 – Park/Neutral Position Switch
42 – The EST signal did not change when the ECM applied bypass voltage to the ignition moduleFound the manual for my code reader tool. Found out about code 12. (forget about that)
Manual says:
Code 31: Electronic Spark Timing (EST) circuit open or shorted to ground during engine run.
Fuel Cutoff relay circuit, open or shorted to ground.
Direct Ignition System (DIS) Fault, bypass circuit open or shorted to ground.Looks like I have at least found out a few things so my efforts have not been in vain. I have found that I more than likely do not have tranny issues. (Thanks, God!) I also know that a lot of this repair may have to be done with a multimeter, which I have, but my once vibrant, flexible body is not suited for twisting into odd positions like it used to. I also am not good with using a multimeter to run down circuitry. Looks like it might be a job for my shop. Let them have the headache, then all I have to do is hold on to my wallet!
Thanks for all of your answers, guys!
Sorry Eric, don’t know how I can make pic smaller. I shoot in RAW..Looks like someone’s been into that engine harness. That MIGHT have something to do with it. I really don’t like those types of electrical connectors I see. You’re right though. At this point it’s likely going to be a bunch of voltage checks to verify the operation of the components in question.
BTW, all you need do is goto the ‘Codes’ page on this site, select OBDI, and then select GM, and this is what you’ll come up with. You can also type GM codes into the search box at the top of this page.
Keep us posted.
UPDATE: I have changed out all the plugs, made sure they all had a good connection. Serviced the IAC valve and MAF Sensors, MAF seemed very clean, IAC had some residue and a bit of carbon forming around the cone part. Black, sooty…
The spark plugs that were installed were the wrong kind, Autolite…yuk! Replaced with good old fashioned Ac-Delco. I like looking at the old plugs when removed from a car or truck. “If eyes are the window to one’s soul, then spark plugs are the window to your engine’s innards.” (Eric, You may use my quote if you like) :woohoo: The removed plugs were platinum, were worn funny, not flat, but were rounded, like the tip of a pencil. They were dry, very clean, almost white like new ones. What is this a sign of?
To conclude, the old girl seems to run better, does not stumble, cough, or fart when cold; and I don’t seem to have the slipping feeling when driving up a grade (when shifting from one gear to another. Now my only problem is a bad switch for the electric trunk closer. It works sometimes. The “trunk ajar” idiot lite stays on on the dash, even though I know it is closed. Sometimes when I have to go into the trunk, I can’t get it to latch. I replaced the motor for the latch about 2 years ago, so I am hoping that it is still o.k…as they are very expensive. Might just be the electric switch which I replaced about 5 years ago. They are only about 20 bucks or less. If I could find a way to disable the switch and just close and open the trunk in the conventional manner, I would do so. Problem solved forever.
It is always something…
A good tune up with the right parts can do wonders. If you cleared the codes and they haven’t come back, you may be in the clear.
As for the trunk latch. I think all that stuff is contained in the latch assembly but without a wiring diagram I really couldn’t say. This might help you though.
http://www.ericthecarguy.com/faq/solving-automotive-electrical-problems
Good luck and continue to keep us updated. In fact, you might consider starting a new thread for the electrical issue. It helps our database if you do it that way.
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