A friend’s family car - 2007 S40 in good condition 150k miles, owned/maintained since 2008. The coolant system octopus split at the junction by the T-stat. We replaced the t-stat and octopus and it’s now not starting and I’m getting the “500 engine/rpm sensor” fault code. I can’t find where this is located to see if we damaged it or disconnected it and forgot to re-connect. We did have to lift the engine to get the airbox out so possibly the wires were stretched or something?
I checked the Volvo parts diagrams and it was no help whatsoever.






