External temp sensor

[Stempy]

Can it be calibrated via Lexia as my replacement one reads about 5 degrees too low?

[Mandrake]

Sounds like its just not the right spec sensor Stempy...

I could be wrong but I doubt there is a calibration option available in the Lexia - there certainly isn't on a Xantia, and my Xantia temp sensor is very accurate. (agrees within 1 degree with my house outside temp sensor - at least when overcast so the sun isn't shining on the wing mirror...)

Doing a calibration at the factory as each car is assembled makes no sense from a mass production perspective - the sensors will be made to a spec, they get fitted to the car and that's that.

The problem with trying to calibrate it is if the sensor is the wrong spec you don't know whether the error is just an offset error or there is also a scaling error. So you would need to do a two point calibration at two widely displaced temperatures, not just adjust it until the current temperature reads correct. Not easy in the current climate...

If its an ebay jobby I would just send it back and try your luck elsewhere!

[Stempy]

Yes it was an eBay jobby. Maybe sourcing an original Citroen item might be the best idea. Or maybe I could be a real ponce and add a trim pot:-)

[Mandrake]

Yes it was an eBay jobby. Maybe sourcing an original Citroen item might be the best idea. Or maybe I could be a real ponce and add a trim pot:-)

Yeah I was going to suggest a series resistor (if the sensor is a PTC type) but then you muck up the resistance/temperature slope (if it was ever right in the first place!) since some portion of that total resistance doesn't change with temperature...chances of getting an accurate reading from high to low temperatures by just adjusting series resistance at one temperature aren't good.

If it was me I'd probably send it back on principle as I hate receiving parts that just don't work as advertised. (Such as dead on arrival MAP sensors, oxygen sensors that aren't the right type etc )

[Stempy]

An original Citroen item is £25 and this one was a third of that so I guess you get what you pay for.

[Northern_Mike]

I bought a £8 eBay one for my C5. It was ok at temperatures above 7c (measured with our thermometer) but seemed to read 4 or 5 degrees lower than actually temp if it got me much lower. It said minus 9 one morning. I'm not sure that was right. I didn't even put a coat on.

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[Stempy]

Mine keeps bleating, telling me there's a risk of black ice whether it's freezing or not

[Northern_Mike]

Yes . Mine did that. "ICE ALERT" until the edge of madness. .

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[Mandrake]

Thankfully my Xantia only flashes an innocuous little snow symbol on the clock - progress is not always progress!

In most cases the fact that its freezing cold outside and the ground is slippery to walk on clues me into the risk of ice of the road...

[Stempy]

Yes it can be quite annoying being told you have forgotten your seatbelt just because you have turned the ignition on