A8_novice

So the G17 sensor is the one in the front of the A/C condenser, right? Has anyone put their hand on the G89 sensor? I understand its in the airbox, but I could not find it. in a 2000 A8 if it makes a difference.

As an aside, its pretty frustrating how they used 2 sensors and then averaged the signal. WTF? that doubles the chance for failure. If instead they had added a little logic to the system they could have cut the chance for a signal failure in half.

silverd2

They "may" average these 2, but Bentley wiring diagrams show G17 going directly to the outside air temp display and G89 going directly to climate control.

G17 doesn't even read correctly until the car has been in motion a while.

G89 always reads real-time air temp entering HVAC.

G89.jpg?t=1305896526

A8_novice

From what I can see in the climate control, there is a time weighted average happening between those 2 sensors, unfortunatley the G89 sensor is reading -40, so the car very quickly reacts to turn off the AC compressor. and blow hot air.

My plenum has a hole with a rubber plug in that location...anyone seen an alternate location for G89?

silverd2

Interesting...so does mine(?)
I'll ask around...have never looked for it before and Bentley is no help this time.

jakematic

This is for 2002 on, but may help:

http://www.audi-portal.com/en/diagno...ors_17858.html

-Jake

silverd2

Interesting...now I'm curious. Gonna pop off the screen tomorrow and look.
Has to be in the HVAC intake to do it's job.

silverd2

Nope, not visible under the screen in my car. I don't know where they hid it...Bentley fell down on the job again.

This is under the hood of my '01 A8:
G89missing.jpg?t=1305987124

jakematic

Found an ETKA catalog in Russian with the following graphic.
Number 10 is the part in question.
And no, I can't leave it alone - drives me batsh*t crazy when I can't find things

http://translate.google.com/translat...257%2F&act=url

Added bonus: found this parts list PDF.
Unfortunately it doesn't confirm the sensor location but may come in handy.
http://www.audipages.com/partslist.html

silverd2

I haven't stopped lookin either, but..

I don't know, I found that one and one just like it on the other side in Bentley drawings....left and right vent temp sensors G150 and G151.
I think the offending G89 is still located elsewhere.G150151.jpg?t=1306008064

silverd2

PS. For anyone who hasn't seen this...all Audi/VW electronic climate control systems have built in user diagnostics which can be accessed in the car WITHOUT Vagcom or any kind of tool. Different models have different access procedures and different code designations.

Really cool...you can read values on every sensor and flap in the CC...and then some.
Here's my post about the facelift A8/S8 codes:

https://www.audiworld.com/forums/sho...odes+revisited