Skoda external air temperature indicator problem

[Graham J]

Skoda Octavia Elegance TDI PD - 2 litre diesel, June 2008, about 102,000
miles.

External air temperature display sometimes shows correct temperature ,
and sometimes drifts downwards, wavering between +15 degrees and -35
degrees. Generally indicates a bit warmer in warmer weather, so -20
rather than -35. Fault started about last November (i.e. 2015)

Sensor has been replaced - to no effect.

If sensor is disconnected an error indication shows and the engine
cooling fan runs flat out - sounds like a hovercraft!

I measure sensor with a meter - shows resistance consistent with air
temperature - I found a table on the web showing the values to expect -
can't find it now ...

I fit a fixed value resistor - 470 ohms should indicate about 10 degress
- but it wavers about just like the real sensor.

So the sensor is not faulty. Its nearby connections and cables look
fine. Can't find anything to tell me where the other end of the wiring
goes.

In cold weather, if temp gauge shows falling temperature the cabin air
temperature increases, suggesting that the climatronic system is taking
input from the external air temperature sensor.

Now that we have warmer wether, the aircon seems to work intermittently
- if the external temperature is indicated as below about 5 degrees the
a/c does nothing, but if the external temp is (say) 16 degrees the a/c
works as expected.

Can anybody confirm whether the external air temperature is used by the
a/c control system, please? If not, then perhaps my first check is to
see if the fluid in the a/c system is low.

Has anybody any suggestions for fixing the problem with the sensor? Or
is it possible to tell the a/c and climatronic to ignore it?

The engine runs OK so I don't think its misleading readings are fed to
the ECU ..

TIA

-- Graham J

[Steven Langdale]

The A/C won't come on if it thinks the external temp is too low. It's too prevent it frosting up.

[Graham J]

Post by Steven Langdale
The A/C won't come on if it thinks the external temp is too low. It's too prevent it frosting up.

This seems reasonable, but contradicts what two separate indy garages
have told me. Is there any documentation from Skoda that will confirm
your opinion?

[Chris Whelan]

Post by Graham J

Post by Steven Langdale
The A/C won't come on if it thinks the external temp is too low. It's
too prevent it frosting up.

This seems reasonable, but contradicts what two separate indy garages
have told me. Is there any documentation from Skoda that will confirm
your opinion?

Don't know about Skoda, but every car with A/C I've owned turns it off at
low external temps.

Might be worth a trawl through here:

http://www.briskoda.net/forums/

and then asking there perhaps?

Chris

[b***@gmail.com]

Post by Graham J

Post by Steven Langdale
The A/C won't come on if it thinks the external temp is too low. It's too prevent it frosting up.

This seems reasonable, but contradicts what two separate indy garages
have told me. Is there any documentation from Skoda that will confirm
your opinion?
--
Graham J

Dear Graham,

I'm facing exactly the same problem with the A/C and temperature readings. I have same vehicle i.e Octavia ii PD 2008 model.. I almost done same things as you have done , replaced the sensor 2 times but issue not resolved.

did you sorted out the issue in your car ?

If yes , please share how you have resolved it ..

Best Regards
Baskaran.V

[a***@gmail.com]

Post by Graham J
Skoda Octavia Elegance TDI PD - 2 litre diesel, June 2008, about 102,000
miles.
External air temperature display sometimes shows correct temperature ,
and sometimes drifts downwards, wavering between +15 degrees and -35
degrees. Generally indicates a bit warmer in warmer weather, so -20
rather than -35. Fault started about last November (i.e. 2015)
Sensor has been replaced - to no effect.
If sensor is disconnected an error indication shows and the engine
cooling fan runs flat out - sounds like a hovercraft!
I measure sensor with a meter - shows resistance consistent with air
temperature - I found a table on the web showing the values to expect -
can't find it now ...
I fit a fixed value resistor - 470 ohms should indicate about 10 degress
- but it wavers about just like the real sensor.
So the sensor is not faulty. Its nearby connections and cables look
fine. Can't find anything to tell me where the other end of the wiring
goes.
In cold weather, if temp gauge shows falling temperature the cabin air
temperature increases, suggesting that the climatronic system is taking
input from the external air temperature sensor.
Now that we have warmer wether, the aircon seems to work intermittently
- if the external temperature is indicated as below about 5 degrees the
a/c does nothing, but if the external temp is (say) 16 degrees the a/c
works as expected.
Can anybody confirm whether the external air temperature is used by the
a/c control system, please? If not, then perhaps my first check is to
see if the fluid in the a/c system is low.
Has anybody any suggestions for fixing the problem with the sensor? Or
is it possible to tell the a/c and climatronic to ignore it?
The engine runs OK so I don't think its misleading readings are fed to
the ECU ..
TIA
-- Graham J

Did you ever sort this out? I'm in Australia and our skoda octavia 2008 does exactly what you have described. I've replaced the sensor and the climate control panel in the front but no joy?

[b***@gmail.com]

Dear Graham,

I'm facing exactly the same problem with the A/C and temperature readings. I have same vehicle i.e Octavia ii PD 2008 model.. I almost done same things as you have done , replaced the sensor 2 times but issue not resolved.

did you sorted out the issue in your car ?

If yes , please share how you have resolved it ..

Best Regards
Baskaran.V

Post by Graham J
Skoda Octavia Elegance TDI PD - 2 litre diesel, June 2008, about 102,000
miles.
External air temperature display sometimes shows correct temperature ,
and sometimes drifts downwards, wavering between +15 degrees and -35
degrees. Generally indicates a bit warmer in warmer weather, so -20
rather than -35. Fault started about last November (i.e. 2015)
Sensor has been replaced - to no effect.
If sensor is disconnected an error indication shows and the engine
cooling fan runs flat out - sounds like a hovercraft!
I measure sensor with a meter - shows resistance consistent with air
temperature - I found a table on the web showing the values to expect -
can't find it now ...
I fit a fixed value resistor - 470 ohms should indicate about 10 degress
- but it wavers about just like the real sensor.
So the sensor is not faulty. Its nearby connections and cables look
fine. Can't find anything to tell me where the other end of the wiring
goes.
In cold weather, if temp gauge shows falling temperature the cabin air
temperature increases, suggesting that the climatronic system is taking
input from the external air temperature sensor.
Now that we have warmer wether, the aircon seems to work intermittently
- if the external temperature is indicated as below about 5 degrees the
a/c does nothing, but if the external temp is (say) 16 degrees the a/c
works as expected.
Can anybody confirm whether the external air temperature is used by the
a/c control system, please? If not, then perhaps my first check is to
see if the fluid in the a/c system is low.
Has anybody any suggestions for fixing the problem with the sensor? Or
is it possible to tell the a/c and climatronic to ignore it?
The engine runs OK so I don't think its misleading readings are fed to
the ECU ..
TIA
-- Graham J