Cemoto

Hello All,

I noticed on my "new" car that the AC works great with plenty of air coming from the dash vents, but when the AC is off that no fresh air was coming from the dash vents or floor vents.

When plugging in my new to me hammer, it listed this fault shown.

After searching a few threads and looking on Ebay to see what the servo motor even looks like, I'm still trying to figure out which it may be. Glad it is not boxed inside the fresh air box as I've seen some on other cars are placed.

I've attached a photo below and am figuring the red arrow points toward it, but am still unsure. Would someone who has been there before confirm? Thanks!

I'm still learning all the various functions of the hammer, and I know there is a way to active (test) all the servo motors on the car and that will be my next step.

Any tips or suggestions are surely welcome!

Thank you very much.

Regards,

.

pp000830

I have this same code too. AC and heat is good, all functions seem to work so I feel the error code is implausible and so I ignore it and life is good.

Cemoto

Thanks but I like fresh air! I don't need/want to run AC all the time.

Figured out which one it was by looking a little further.

Regards,

.

bcameron59

Well? Which one was it?

therossinator

Fresh air is the middle one, green arrow. I have not figured out how to cycle mine without my T-OBD. Perhaps patience would help.

To remove the fresh air servo you will also need to remove the footwell flap servo (red arrow). Once you have the fresh air servo out you can use a couple of flat screwdrivers to pry open the case and clean the electrical contacts within.

Also there is a vacuum operated flap that is visible when you remove the ccu. Just look into the hole and you will plainly see the vacuum operated recirc flap that often has disconnected linkage. A zip tie fits the bill well. Also check that the vacuum line is actually connected, could cause a vacuum leak if not.

ToreB

The middle (green arrow) is the fresh air servo. There is no need to remove other servos to change it, but you will have to set the arm in about the 4-o'clock position to get it out of the metal bracket. To set the arm in position (requiring that the servo moves) is easy: Get ready to remove servo connector, set the CCU temp control to max temp, and turn on and off the ignition to get the servo moving. (it shall park in the closed position when ignition is off) Pull the connector off when the arm is the correct position.

It is not uncommon to have lots of stored fault codes in the CCU, you should note, and clear them, and then maneuver all CCU functions to see if any codes reappear.

The 993 CCU have a servo test function, but this is not a reliable test since it moves the servos without using the feedback from the servo. The function is only useful for moving the servos to extreme positions for a mechanical flap test. I have made a DIY servo test procedure that will enable you to determine any servo faults.
Cheers,
Tore

nine9six

I just witnessed exactly what Tore states above...

I replaced my fresh air servo about a year ago, but found a bunch of stored CCU fault codes with a durametric reader. I cleared the codes, as all is operating as it should.

Tore, thank you for that peace of mind!

lopro

I have the same reading with my bosch hammer tool aswell.

Cemoto

I had a few minutes tonight to play with it and here are my results.

When on recirc plenty of air blows through the center and side vents.

I had my wife look at the fresh air servo motor while I followed Tore's quick test of moving the temp know from cold to hot - no movement.

My radio removal tools seem to have gone hiding and my quick attempt at making some from a coat hanger failed to deactivate the anchors. I'll borrow some later this week.

I did manage to get under the dash to see if I could find that vac operated flap.

Is this pic of that unit?

You can see the CCU wire connectors.

Thanks for the help.

Regards,

x50type

I found my re-circ had some how been disconnected when the evap was renewed; it quite a job to reconnect it thro the ccu aperture.

x50type

Another photo..

Cemoto

I replaced my servo today with a 32k mile used one. All went well and it wasn't difficult thanks to Tore's suggestion to power the unit so the arm gets in the right spot.

Without that suggestion it would have been much more involved, so THANK YOU VERY MUCH Tore.

There was no need to remove the galvanized bracket, just the two screws, electrical connection, and the snap in place lever.

The job took approx 30 min.

Regards,

.

pp000830

If anyone in the US has a used and non-functional servo available I would like to have it for a frankinservo attempt at a repair. If I develop a successful DIY solution I will share it with all.
PM me with your regular email address and a shipping address and I will email you a pre-paid USPS label to send it to me.
Thanks,
Andy
964 624 901 00 = Fresh air
964 624 902 00 = Defroster
993 572 905 00 = Temp mixing

nine9six

...A very true statement...I spent about two hours before learning how to properly clock and install that stinkin servo.

I'm old and slow to learn, but I figure thats OK as long as I'm still learning

Jbelt01

It’s 90+ outside and I’m reading through these posts troubleshooting weak AC. Center vent temp is 77F. I’m on my back looking under the dash to see if the recirculate servo and door are functioning. The servo arm moves but it’s not connected to the door linkage.

I’m not sure if that’s the source of my weak AC but it’s a start. This knowledge contained in this forum is priceless.