Hi,

I have a 1994 Olds Ninety Eight. The check engine light is coming on and off intermittently. It is running fine, but I have noticed a slight drop in fuel economy. I'm thinking it might simply need an O2 sensor, but I want to be sure before I purchase one. It has 117K on it, so it likely needs replacing anyway.

I have an OBDII scanner that will not pull the codes. I get an error message. I took it to Auto Zone and they got the same message with their scanner.

After some research online, I see some 1994's-1995's have the OBDII connector but are indeed running the old OBDI system, and that OBD was not manditory until 1996. So I have a feeling that is what I have here, an OBDI system with an OBDII connector.

I have a scan key device to read the codes on my 1992 Olds 88, which is easier than climbing under the dash to jump the a-b terminals. This device has a different plug for the old OBDI system, so it of course will not work on my Ninety Eight.

How do I pull the codes on this car? Is there a way to jump terminals like on my older car? I certainly don't want to fry the ECM messing around!

Thanks in advance,
Michael

If the Diagnostic Connectors are different on you 92 and 94, the 94 has OBD II, and you can NOT do any " terminal Jumping" to cause check engine lite flashes to count Codes! Will our scan tool actually work on a "Known Good Source" (vehicle that check engine lite is not on) ? Car may have computer problem, AND just because there is a code present does Not nessessarily mean that the particular sensor is bad, it Does mean that the "computer" has detected a problem within that "Circuit"(computer, wiring or sensor). Most local libraries have" Factory" or Chilton service manuals.

If you have the old 12 pin Data Link Connector (DLC) you can jump pin A to pin B and turn the ignition switch to the run position to flash the code.
But if you have the newer style 16 pin DLC, you must use an appropriate scan tool with current software loaded.

Attachment 14981

I have a 1994 Olds 88 LSS. I had the same problem in trying to read the check engine codes from the output port. There is only one way I know of the get the codes. Forget jumping the A & B terminals as that does nothing. You have to get a AutoXray CodeScout 2500 reader. AutoXray has a cable which connects to the 16 PIN port but can read the OBD I codes. The cable part number is 20211. You can get this cable for $29.99 from tradevar.com. That is the cheapest I found and very fast shipping. When connecting the 2500 reader it will ask what type of connection you want to make and you select GM 1994-1995. It will tell you to connect the "Blue" cable to the reader and then to the output port on the car. Press the "READ" button and it will find your error codes immediately. I had a P0122 which is a faulty Throttle Position Sensor Low problem. I replaced the sensor and cleard the code. The check engine light went out and I check the system again for any errors and there were none. I got my 2500 reader used on eBay for $72.00. I was lucky as this one was like new and came with OBD II cable but like I said I had to order the specific cable to read what is called the OBD 1.5 codes. Hope this helps as I got lucky and did not have to go to the dealer for a good does of screwing!! GOOD LUCK!

I have a 1994 olds regency and have taken to autozone to read codes their code readers will not communicate... you need to use a more sophisticated scanner such as a snap-on... I did this and was able to retrieve codes.