Great, thanks for that link. If I need to replace the resistors, that's a massive help.

Given the error code did highlight the air quality sensor, if anybody else has tips on how to replace that i would still be keen to hear your advice.

Cheers Dave

Thanks for the suggestion, a resistor sounds much cheaper than the sensor to replace. Does anybody know where I can find a step-by-step guide to replace either the resistor or air quality sensor?

Thanks again!

An error code scan on my 2004 XC90 2.5T indicated that the air quality sensor wasn't working and hence needs replacing. Can anybody please tell me how to replace the sensor? Background: The air con started working erractically with the blower speed changing lots for no apparent reason. We noticed th...