I have a 96 850, and was looking to reset the ECU for the automatic HVAC. My Haynes manual shows the procedure to do this using the diagnostic ports in the engine bay, but my car is OBD II, and does not have this port. Does anyone know how to do this on OBD II vehicles?

Thanks

My problem is that in pre-OBD II 850s, one could reset the damper motor endstops using the diagnostic port. There is a sequence to follow, and the damper motor will move from stop to stop, and reset itself. I'm trying to figure out how to do that on OBD II cars without the diagnostic port.

Thanks

To reset the stops on the OBDII cars my guess would be to disconnect the battery for a few minutes then run through the standard reset setup:

With ignition OFF.
Blower switch in MANUAL set to half speed.
Recirculation mode ON.
Left and Right Temperature selectors to 72 degrees.
AirFlow selector set detent between Ventilation and Defrost detent.
Airconditioning switch set to AUTO.

Then reconnect battery and drive the car around at over 20 mph for more than 5 minutes. The A/C and Recirc LED lights may flash during this period indicating self test mode.

See what that does. Disconnecting the battery causes the ECC to return to it's default settings and run through a self test. This should reset all stops.



Mike

Sorry about my ignorance but what is: "reset the damper motor endstops" ?
--
Ken

Cool, I'll try that and post whether it worked or not. Thanks!

The diagnostic port is under the "coin tray" next to the cigarette lighter on the center console. Just lift out the tray. HVAC codes can also be read. If you don't have your own OBD code reader, go to Autozone.

Klaus
--
98 V70Rawd(101Kmi), 95 854T(85K mi), 75 164E(173K mi)

If no reader just disconnect the battery for about two minutes.

As aluded to, you need a code scanner/resetter. the 96 and on years went to ODBII, whereas the Haynes is referencing for pre 96. Equus 3100, for $120, is one option for a scan tool, and others the Actron which is about $200. I personally use the Equus 3100 and it is fine for me, but I do not know if it will help you with your issue. Is you check engine light on, or any other light?

BB

Does that fault code show up on the reader you used? You should be able to clear it from whatever reader showed you the code. But most of the cheaper <$300 readers can't even see that Air Conditioning code.



Mike

The ECC module is the same as the pre '96 ones.

So you can read codes etc. by using pin 6 of the OBD socket.

Connect a LED test lamp between pin 16 Batt + to pin 6 (ECC).

Connect a push to make switch between pin 6 (ECC) and pin 4 or 5 (Ground).

You can then use this setup in the same way as the engine compartment OBD connectors on the pre '96 cars.