OBDII diag port

[92cavquest]

The car is a 1997. All electronics including entire wiring harness and all computers/controllers are from a 2000 Grand Am. The engine starts and runs. I've ordered Hp Tuners and I'm ready to tune it.

Problem is I can't get my OBDII diag port to work. I've verified that it's gettin power, ground and that there's continuity in the class 2 data wire to the bcm. I'm getting ready to buy hp tuners but need to get this working first. I have alldata and I'm pretty handy with a multimeter but this class 2 stuff baffles me.

When I hook up my OBDII scanner it says "waiting for vehicle to respond" and then it times out after a couple of minutes. Any help is greatly appreciated.

[92cavquest]

Maybe another area would be better suited to my question?

[pocket-rocket]

I would try reconnecting the BCM and the PCM. If that doesn't work, see if you have a friend with the same type of vehicle to swap PCMs for a short bit to test.

[92cavquest]

Lol. I already tried that. Unfortunately it wasn't that simple. I've unplugged every module that has class 2 data wires one at a time and it still made no difference. I'm at a loss.

[pocket-rocket]

Have you tried your scanner in another car? How do the connections look inside the OBD port?

[Schmieder]

I had a problem once similar. A fuse was blown by the glove box. Apparently the vehicle can run fine w/o it (the fuse for the OBDII Port). Not sure if there is power to the OBDII when the data fuse is blown.

I would double check all your fuses because your issue is similar to mine a few months ago.

Do you have a wiring schematic? I would run new wires from the ODBII to the corresponding PCM pins to test for wire failures, shorts, ect.

Make sure the PCM pins are identical. I did a PCM swap and had to adjust 1 wire for my alternator. Even vehicles which say they are the same v6PCM controller can have different pin outs between yr/make/model.

Oh and, seems dumb but, do you have the ignition turned to on/engine off? Don't hate me for the question, some people actually forget and over look that one simple thing.

Also, make sure ALL wires to the OBDII Port are wired up right. I think there is a ground and another feed, 2 data lines, I'm not positive but I do know there are more then 2 wires running into mine.

[hookdonspeed]

im not sure how diffrent the 97 wiring is from 98, but on my fiero swap, using a 98 ecu, there are 2 data wires for the PCM, a tan one (pin9 on the obd2 dlc pin 15 of blue ecu connector) and a purple one (pin 2 of the obd2 dlc and pin 59 of the blue ecu connector) the san is listed as serial data (UART) and the purple as class 2 serial data.

2 grounds (pins 4 and 5 on the DLC)

and 1 power (hot at all times, pin pin 16 on the DLC)

[TurboGTU]

disconect the pcm and other moduals.
ohm pin 2 on the obd2 port and the pcm wire harness.
One pin should have 0-3 ohms on the pcm harness. If not, there's a open wire. Trace it and connect it. If yes, ohm that same wire and ground or positive, there should be infinate ohms. If resistance then that J1850+ is shorted to power. trace and isolate.
The same for pin 10 on the obd2 port to pcm wire harness.