Unlike what it's being said on Internet, it's not only about a bad chip. Several resistors also go bad. The whole motherboard needs to be tested and fixed. This company is fixing them in Europe https://volvodiagnostic.com/ and you can also find services on Ebay . If you only get a check engine light...

Are the resistor values listed - if I recall they are SMD. Generally they will either short or go open. Go through the board with this idea in mind. The capacitors are another issue as they generally are not marked. You can try measuring and comparing Original vs Donor. Everything below assumes the ...