OBD Port Question

[driver456]

I have a 97 C5 auto I have the dreaded blinking a/c light.Freon is good,Pressure is good.When I hook up the scan tool and go to bidirectional then control panel and click on a/c on the control panel my a/c works fine,No blinking light,The light stays on on the a/c button,Ice cold a/c,No problems.My question is,Does it bypass the PCM,What wires in the OBD port does it use to turn on the a/c.Does it ground it out or send voltage.Would anybody have a wiring diagram from the OBD port to the HVAC system.I'm just trying to narrow it down.....Thanks..........Paul

[lsxtech]

its grounding it though the pcm, not the OBD connector, something is keeping your pcm from turning the a/c on if it works with the bidirectional control

[lsxtech]

I believe the vettes have a evaporator temp sensor, if you pressures are good and switches are good i would look at the evap sensor

[driver456]

I believe the vettes have a evaporator temp sensor, if you pressures are good and switches are good i would look at the evap sensor

Would you know where that is?...............Paul

[lsxtech]

have you scanned it for any codes

[driver456]

have you scanned it for any codes

Yes,No codes.............Paul

[lsxtech]

locate evaporator should have wires coming out of the box somewhere that go to a connector, i'm not at the shop right now so i can't look up the exact location of the connector, but if you can wait till tomorrow i will get all the info you need

[driver456]

locate evaporator should have wires coming out of the box somewhere that go to a connector, i'm not at the shop right now so i can't look up the exact location of the connector, but if you can wait till tomorrow i will get all the info you need

That would be awsome dude,I'll wait.....Thank you...............Paul

[mnotx]

I have the GM online manual. Let me know if you need any of the diagnostic or repair procedures. I can send anything you want by e-mail. Just let me know what you need.

Also, is the HVAC automatic or manual?

Milt,
mnotx@grandecom.net

[driver456]

I have the GM online manual. Let me know if you need any of the diagnostic or repair procedures. I can send anything you want by e-mail. Just let me know what you need.

Also, is the HVAC automatic or manual?

Milt,
mnotx@grandecom.net

I'm not sure what you mean about the HVAC being auto or manual.Its a dual zone,I know that.I have the 4 manuals,But I couldn't find anything with the OBD port.Lsxtech kind of answerd one of my questions.I'm just trying to narrow it down,Maybe someone will come up with an answer......thank you ...................Paul