Enso

Anyone have a CCU schematic please?

thanks
Glenn

jo-hans

Check Tore's site: http://www.bergvillfx.com/ccurepair.html

Enso

Tores site doesn't seem to have a CCU schematic, but great info

x50type

Apparently no one can locate the schematic!

phoneyman

Im confused. Is it not this?

http://www.bergvillfx.com/images/993hvac.gif

deekay911

I think that's just the wiring diagram of the whole HVAC system. I think the OP was looking for the electronics layout of the CCU itself, for troubleshooting and/or repair.

Enso

this is everything around the CCU but not the unit itself

ToreB

Myself and others have done extensive work to find the CCU schematics, but have not yet been able to get it. This is the same situation as the other Porsche electronic units. The vendors are probably not allowed to disclose them due to their contract with Porsche, and most often does not have them at all. I'll send you a bottle of Champagne if you manage to get the schematics.
Could I ask why do you need it?
Cheers,
Tore

Enso

Hi Tore
yes a couple of things seem wacky
- the CCU internal fan is always running
- the heater is always blowing heat from fan setting 2,3,4
- when the fan is set to blue or cold the front fans run at radical speeds blowing hot air
heres the spooky part, when everything is shut down there is a light rubbing sound coming from the front
I disconnect all HVAC motors, opened the footwells and removed the motors checked them both and cleaned them, they are all good
BUT when the motors are plugged in there is a varying voltage going to all of them. this is what is causes the noise, the motors are getting a varying voltage all the time, even when the the key is out of the ignition, but not the flaps don't move
I exchanged face plate with another and the voltage to the motors seems to stop, but the CCU internal fan keeps running

here are some pics

Enso

CCU gone bananas

JasonAndreas

Bad Transistor

ToreB

You have at least two problems: A bad T1 transistor, and the servo you have pictured needs to be changed.
Cheers,
Tore

peter-997

Hi.
My internal teperature sensor of the CCU is showing the wrong value.
59°C at 19°C.

When I am cross changing the front with the buttons to a working CCU the failure is moving with it.
So the failure is not in the CCU itself it is in the front plate with the buttons and potentiometer.

Who knows on which pins of the flat cable are the relevant resistor values for the internal temperature?

regards
Peter

peter-997

It is the sensor itself.
Does somebody know which kind of resistor it is?

Is it a NTC or a PTC and which temperature curve must it have?