^{Hi all}

^{I have been having problems with my outside air temp sensor showing a consistent 10C below ambient on both the clock cluster and the climatronic thingy. This causes the air-con not to come on a demist the windscreen in the morning. I have changed the sensor behind the front bumper but this hasn't solved the issue. I checked the supply voltage to the sensor and it was reading 5v. should this be 12v?} 

^thanks

^Ant

 

p.s. I'm also having driver door issues central locking and micro switch just in case they may be related. .  

Have you plugged VCDS into it as it might show why? I also pulled this from a workshop manual.

 

Testing ambient temperature sensor -Gl7-

 

Special tools, testers and aids required

 

- Hand-held multi-meter, e.g. V.A.G 1526 A

- Remove left ventilation grille.

- Take out ambient temperature sensor.

- Separate connector of ambient temperature sensor.

- Connect handheld multi-meter to the contacts of the ambient temperature sensor for resistance measurement.

 

Specifications:

 

Temperature Specification

-30⁰ C

Approx. 18265Ω

0⁰ C

Approx. 3300 Ω

20⁰ C

Approx. 1184 Ω

50⁰ C

Approx. 359 Ω

 

 

 

 

 

- lf that specification is not achieved, replace the ambient temperature sensor.

- lf the specification is achieved, then test the cable to the ambient temperature sensor.

- lf the specification for the resistance and the cable to the sensor are correct, then replace the dash panel insert.

 

Hope that helps in some way?

Thanks. Yes it helped. The sensor appears to be working correctly. Did the workshop manual have a wiring diagram at all please?.

sorry i have had it on the VCDS but some time ago. (this has been an on going problem) and it flagged the sensor but wasn't told much more then that. I wonder if anyone is local to Trowbridge in Wiltshire may have one for me to kindly plug in?

No sorry it did not. You might be able to download one from the net? There is a self diagnosis function on the climatronic system try this link:-

Have you plugged VCDS into it as it might show why? I also pulled this from a workshop manual.

 

Testing ambient temperature sensor -Gl7-

 

Special tools, testers and aids required

 

- Hand-held multi-meter, e.g. V.A.G 1526 A

- Remove left ventilation grille.

- Take out ambient temperature sensor.

- Separate connector of ambient temperature sensor.

- Connect handheld multi-meter to the contacts of the ambient temperature sensor for resistance measurement.

 

Specifications:

 

Temperature Specification

-30⁰ C

Approx. 18265Ω

0⁰ C

Approx. 3300 Ω

20⁰ C

Approx. 1184 Ω

50⁰ C

Approx. 359 Ω

 

 

 

 

 

- lf that specification is not achieved, replace the ambient temperature sensor.

- lf the specification is achieved, then test the cable to the ambient temperature sensor.

- lf the specification for the resistance and the cable to the sensor are correct, then replace the dash panel insert.

 

Hope that helps in some way?

Sorry to hijack an old thread but I suspect a faulty ambient sensor on mine. Disconnected sensor and I have 0.82ohms. Based on the readings above am I correct in saying mine is kaput?

Yep ! that's near enough short circuit