I have a good friend w/ an '94 Olds 88 Royale 3.8 that is getting an intermittent MIL (Service Engine Soon).

It sets when decelerating from 65mph or more (but NOT from 64mph or less), then disappears later, but certainly when the engine is shut off and re-started.

I understand it may have a 12 PIN OBD I or a 16 Pin OBD 1, ("OBD 1.5"?), or even a complete 16 Pin OBD II depending upon the VIN.

I am trying to help him long-distance (I am not where the car is).

Anyone know for sure what type OBD and DLC connectors '94 Olds 88 (3. have?

My "guess" is an EGR code from the symptoms.

The car runs perfectly w/ or w/out the MIL illuminated except for the typical reluctance for the torque-converter to unlock in OD with light/moderate throttle application, causing a bit of shudder due to the low RPM. I had a '96 Bonneville that did the same thing. The shudder thing was present well before the MIL illumination that just started, plus the shudder only happens on acceleration, while the MIL illuminates briefly only during deceleration, and then ONLY if he was at 65mph or above when letting off the accelerator on downhill sections of Interstates.

Thanks,
Bob

the difference in obd1 and 2 should be fairly obvious if you google it and look at the connector. the trouble with 1.5 though is it looks like 2. so if you have 1 it should be obvious but most of the 94'* with the 2 looking connector being the 1.5. basically a 2 reader wont read the codes from it

I had him send me a photo, and it'* the 16 in OBD II style DLC.

I guess that means its OBD 1.5 in a '94 then? I guess no '94s had full OBD II?

Is there a way to read the codes w/ an OBD 1.5 scanner (if there is such a beast)? I only have OBD II scanners.

BTW, the photo he sent showed that there are pins at #4and #5, unlike some OBD 1.5 cars that are missing pin #4 (#5 is ground and is there on all 16 pin cars).

One site said you can do the paper clip test (like connecting A and B with the 12 pin OBD 1 connectors), by connecting #4 and #5 instead, but don't want to fry his computer w/ being sure.

you have to use a obd 1.5 scanner for that because the codes are like the obd2 ones, for example p0300, where previous obd1 is like 14 and the cel can blink it out. and the obd2 ones wont work it has to specifically say gm obd1.5

OK, so the post that said if you have both a Pins 4 and 5 (and a 16 Pin DLC) you can use the paper-clip method (where if you are missing the #4 on a 16 Pin DLC you must use an OBD I.5 scanner) is wrong, and if you have the 16 pin DLC you MUST use an OBD 1.5 Code Reader, period.

THE ONLY "blink-codes" are then from Pre-1994 (or the odd other one) cars that have 12-Pin DLCs.

Thanks.