OBD1 code reading trick

[94 formula]

I took my friend today to a garage to pick up his car. I went in with him and got in a conversation with him about my firebird and he told me he used to work for a GM garage and learned that if you get a SES code you can put a bent paper clip in the upper and lower holes of where you plug in a scanner with your car tuned off when you flip the key to run the SES light will flash for the number of times your that your code is. It will repeat it two more times then show another code if you have any more. Ex.. code 12-the SES will flash once stop for about a second then flash twice quickly. It will repeat that two more times then. I tried it on my own car and it works but only on OBD1's. I was just wondering if anyone else knew about this.

[tabahr]

quoted from Injuneer...
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"ONLY the 1993's can be flashed with the "short the pins" trick... does NOT work on 94 and up.

1994 has a 12-pin (OBD-I) ALDL connector, and an OBD-I computer.

It is the 1995 that has a 16-pin (OBD-II) ALDL connector and an OBD-I computer.

Only the 1996 and up models have the OBD-II computer.

You need to use an OBD-I scanner with an OBD-I connector. I can give you a list of the hardware and software scanners that will work on your car."
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end quote....

shorting the pins only works on pre 94. I used to do it on my 88 Iroc. I've tried it on my 94 and the light does flash but the flashes make no sense. There is no pattern. From what I understand they are the computer flashing internal codes, and they have no meaning to us. You cannot flash codes from OBD1.

[94 formula]

It worked on my 94 and wasn't it half way through the year in 94 that they switched to the 16 pin with the OBD1.

[Craig 94 TA GT]

Hmmm....I tried it on my 94 TA GT. I used that cheapo scan tool that works just like a paper clip (for $30), but it didn't work. All it did was kick the fans on when I turned the key to the "on" position.

Everyone said that the flash codes are 93 only. Maybe it's on very early '94s? I know the tool I wasted my money on said it was compatible with '94s, which got me upset when it didn't work!

[94 formula]

I'm not really sure. When it comes to computers I have no clue all I know is that I pulled the wire off the MAF got the light on then tried it and it worked on mine.

[Joe 1320]

As you found out, 94 and newer require a dedicated scanner.

[Injuneer]

Originally posted by 94 formula
It worked on my 94 and wasn't it half way through the year in 94 that they switched to the 16 pin with the OBD1.

No. I have a very "late" 94 (built July 94), and it has the 12-pin connector, and can not be read by shorting the ALDL pins. What is the serial number of your 94?

[Rob B (shoebox)]

Originally posted by 94 formula
It worked on my 94 and wasn't it half way through the year in 94 that they switched to the 16 pin with the OBD1.

Shorting the pins on a 1994 (or even 1995) will make the light come on, but will not flash any codes. I'm very skeptical about your statement, seeing as GM completely changed the computers from 1993 to 1994 (not aware of any mid-year change)and have never heard of anyone being able to flash codes on a 1994.

[TruckMuddr]

I tried it on my '94 T/A and all it does is turn the fans on, But my '95 Chevy Z71 will flash the codes and they both are 12 pin.

[Rob B (shoebox)]

Originally posted by TruckMuddr
I tried it on my '94 T/A and all it does is turn the fans on, But my '95 Chevy Z71 will flash the codes and they both are 12 pin.

I was specifically speaking of years of F-bodies, not vehicles in general.