HVAC not working

[markwemple]

Got the car back from the tech. Had to have it jumped (first time I've ever had that happen). Anyway, the HVAC controls, defroster and heat seater buttons all aren't working. Also, the shift indicator and winter mode on the tranny aren't doing anything. I checked fuses, they all seemed fine except, I don't know where to look for the 60a fuses in the engine bay to check them. Any ideas?

[BillAileo]

The electronics in these cars are very sensitive to a low voltage battery. Since you had to have your car jumped I would worry first about the quality of the battery before focusing on the electricial componets that are not now functioning.

[markwemple]

I hadn't run it in about a week ( a lot longer than it normally sits) so I'm guessing there is a draw that caused the battery to drop too low.

Called Volvo of Annapolis Service. They said that the jump may have caused the HVAC to need a reboot or software? The only way to tell is to have a diagnosis. Does this sound right?

[markwemple]

Someone suggested removing the battery ground for about 30 secs to reset the system. Did it to no effect.

[markwemple]

No ideas? Anyone?

[jda2000]

to reset the HVAC system, you need to disconnect the negative and the positive battery cable.

Touch both cables together for about 20 seconds, that will reset the system. If that doesn't work, you might need the dealer to reload the software for the HVAC.

[MoeB]

Here are instructions for disconnecting/connecting battery.

[markwemple]

Thanks guys. I will give it a go. Didn't know about turning the key to the 2nd position (on, I guess?) before reconnecting the ground.

[markwemple]

Tried it. No joy. Any other ideas other than the Stealer? Plase remember that the seat heaters, defrosters, winter mode and tranny position indicator aren't working either. Common ground?

[Aviator]

This is a shot in the dark. but give it a go anyway; it seems to fix other anomalies......lock and unlock the car using the key 3 times. Not the key fob....the key....in the door.

Dave.

[markwemple]

Got a call back from the tech. He believes it is the actual unit but I told him that the lights aren working on the tranny indicator or the "w" button. He called in a Volvo specialist but that guy said you cannot reprogram these things. WTF?

[jda2000]

make appt with the dealer for reloading the software.

This might or might not work, but at least the dealer will make the diagnosis that the CCM needs replacement after the software reload doesn't work.:o

[JRL]

You probably don't need software but the system does need to be re initialized (BY YOUR DEALER)!:eek:

[markwemple]

So you guys don't believe that it could be the control or just unlikely? Thanks for the help in advance.

[MoeB]

If it were mine I'd take it to a shop with the VIDA system and let them diagnose it. Some of the electronic engineering on these cars is just plain weird and nonintuitive, e.g., having to press the key fob lock/unlock buttons three times to reset sunroof, climate controls, and visor mirror lamps after a battery disconnect. What owner would figure that out using reasoning??