Hi, my '98 S90 has an 123ECT code that, from what I can tell, is a bad temp sensor with the recommendtion to replace the thermostat at the same time. Try as I might, I cannot find assistance on this for an S90 and none of the help for other models has a layout that looks like mine. Could anyone point me to assistance? Thanks in advance.

 

follow the upper radiator hose to the top of the block - it should connect to a roundish cap - the thermostat is under that. If you remove the cap ( with hose attached) you should see the temp sensor screwed into the housing directly below.

 

Excellent, thanks so much!