Faulty temperature sensor

[hdi_man]

my C5 has a faulty temperature sensor, its reading ~10 degrees under actual temperature and car is telling me risk of ICE.

anyone know how to fix this ? where is it located ?

[wheeler]

the external temp sensor is located in the n/s door mirror at the bottom, it looks like a little black nipple at the bottom of the mirror housing. The new sensor comes with just 2 lengths of wire so you need to cut the old one off & solder the new one on. With this sensor not working you will find your A/C wont work quite as it should either.

[hdi_man]

ah ! thats why my aircon isn't as cold as I thought it used to be !! I will have a look, thanks

[hdi_man]

just had a quick look and can't see how to get the back off the mirror housing. does it just clip off with a bit of force ?

[xantia_v6]

just had a quick look and can't see how to get the back off the mirror housing. does it just clip off with a bit of force ?

Yes but....

1. You will break all the clips unless you know the exact angle to twist it.
2. Even knowing the exact angle will probably break half the clips
3. Removing the back does not help you get to the sensor, you need to remove the glass and go in from that end.

With the mirror glass tilted down, you should be able to see 2 spring wire ends behind the top of the glass.
Push those towards each other then back into the housing and they should spring further out and the glass assembly should pop out.

[hdi_man]

replaced it last night.

actually on the 2008> C5 you need to remove the back of the mirror housing, first I removed the glass and still couldn't get to the sensor.

the back of the mirror comes in 2 parts, upper and lower.
removing the upper bodywork painted part reveals clips to remove the lower black plastic part, when you remove this you will see the sensor.

I cut the wires to the old sensor and used electrical tape to attach the new sensor (soldering would have been better). its all good now and reading proper temperature again !