Best OBD1 tool and how to use it?

Discussion in 'GM Powertrain' started by Big6ft6, Nov 7, 2008.

  1. Big6ft6

    Big6ft6 Rockstar 100 Posts

    I've put in a new TBI engine in my 89 burb.

    of course the CEL is now on. I'd like to check the codes.

    I can find a number of OBD1 scanners on line for sale from $40 to $200. Which are best?

    also, how do they work, the cheaper ones don't seem to have a display??? should they all have a display? Or do some need to be plugged into a computer?
  2. Bleaktrotter

    Bleaktrotter New Member

    These are all questions I have too.
  3. JMoney02

    JMoney02 Epic Member 5+ Years 500 Posts

    A 6 inch lead made of good 12g wire with two slim aligator clips plugged into terms A and B and let the CEL do what its suppose to. When it flashes the 12 code(3 times) then any stored codes. This gives you the same results and a good manual with have the codes for the vehicle listed in the Emission section.
    The OBD2 readers provide more as there are more codes to scan and read. There are not that many for OBD1.

  4. Big6ft6

    Big6ft6 Rockstar 100 Posts

    Jeff, you are giving me WAY too much credit, I'm not as smart as you think I am!

    Could you explain a little better? So I just jump terminals A and B (where are these terminals?) with a piece of wire and based on how many times the CEL light flashes this is some type of code?

    What do you mean "When it flashes the 12 code (3 times) then any stored codes."

    And it sounds like maybe my Haynes manual will have codes in it? Will it also explain the procedure that you mention above for reading the codes? (I'll check when I get home)

    thanks for your help!!
  5. GaryL

    GaryL Epic Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    The terminals he is talking about is in you ALDL connector under the edge of the dash on the driver's side. When you put the wire (I use a large paper clip) between terminals A and B, the check engine light will begin to flash. It will flash two digit codes. The first code will be code 12, which is denoted by a flash then a short pause then two flashes. After this, it will have another pause and then flash the same things twice more. It will flash each code 3 times and then have a longer pause and move to the next code. As an example, a display of 3 flashes, pause then 4 flashes is a code 34. You can decode the codes here ( ), just select your year and engine size and it will give you a list of codes.

    Here is how the ALDL terminals are laid out:
  6. Big6ft6

    Big6ft6 Rockstar 100 Posts

    Holy Buckaroos!! that is awesome! I cannot wait to try it! Thanks a ton Gary!
  7. Springthing

    Springthing Epic Member 5+ Years 1000 Posts

    May as well post my question along with this one, seeing as it's kind of the same question.

    Regarding OBD scanners... I have been looking into getting the laptop versions. They come with the connectors that has the USB on the other end, and has software to do the code reading.

    Has anyone ever used this type of scanner before? Currently use it now? Do you think it offers more (or more easily) options than the handhelds that cost 3,4, and 5 times as much?
  8. JMoney02

    JMoney02 Epic Member 5+ Years 500 Posts


    I have used most of the scanners, I have seen the new versions of the Laptop readers and tuners, but have not fiddle with them yet, but want to, just don't have the good laptop to support it at this time. But, here you go, if you have the Cadillac Budget and can afford, by all means do, if not work with your budget. The jump wire for the OBD1 is most efficient as there are not that many codes, if its the OBD2 then I suggest that all are good, I have several Actron's that I like. I am NOT being carsastic when I speak about the Cadillac Budget, buy what you can afford and what serves your purpose, I believe its called "Personal Preference".

  9. Springthing

    Springthing Epic Member 5+ Years 1000 Posts

    Thanks for the opinion.

    In looking at prices, the reason I was interested in the laptop version is because they are about the same price as some of the less expensive hand-held models. I don't know if that's because there's no "gadget" factor... just a wire and software, or if it's because they actually suck.
  10. MauryFrench

    MauryFrench Rockstar 100 Posts

    Mr. Gary.

    My truck is still not fixed; however I feel like a kid with a new toy. I was able to get a code from my 95 chevy P/U with a plethora of problems.

    Of course in Texas the code makes no sense; [TABLE="width: 90%, align: center"]
    [TD]Coolant temperature sensor signal indicates a temperature colder than -27° F for 30 seconds after the engine has been running for at least 30 seconds.[/TD]
    But at least I can read codes now. This is a new temperature sensor that I installed recently.

    Back to the drawing board, but thanks for this information.


Share This Page

Newest Gallery Photos