What kind of sensor are we talking about here, O2 sensor, temperature sensor?

Seems like there's a short within the AC unit. I think it's best you take it to an independent shop and let them diagnose the problem. I just picked up a nice 2009 S40 2.4i too. So far so good besides the ABS module noise whenever the car starts rolling within 10-12mph (from the first ignition), but...

I just bought a 2009 2.4i FWD (5Sp. Geartronic auto) with only 36,500 miles from a dealer and the car has got the worst gas mileage ever. I spend about $160/mo on fuel driving only 5 days/wk to and from work. Whenever the tank is filled, I reset the trip to 0.00 and by the time it gets to 170-180, t...

I just realized this post should go under the C30 thread. Confusing! Anyway, I found out what the problem is with the 'kick' sound, it is caused by the ABS system when the system does a self-diagnostic test whenever you 'first' turn on the ignition. It will do this within 12mph as stated on pg. 145 ...

Bump???

I just picked up a 2009 S40 2.4i and realized a slight 'kick start' from the engine bay whenever I put it into D and accelerate within 3-5mph miles. The sound is similar to when the Air conditioning kicks in on an older car; kind of a slight crank or a fan clutch type of noise. It would only do this...