Check Engine Fuction
Lets you know if your emissions system or electronic engine controls are not operating properly.
I've had several mechanics tell me it could be a whole mess of reasons, and that Volvos are famous for their check engine lights that come on for little to no reason, and then can't be taken off without very expensive equipment. Most of the time if it's on it's not a big problem, unless you want to pass emissions.
A basic OBDII scantool can read and erase error codes on any volvo 1996 and up. The only time special expensive equipement is needed is when scanning codes for the ABS or Airbag systems. Most auto stores will scan check engine light codes for FREE.
Looking for a Used S40 in your area?
CarGurus has 1,100 nationwide S40 listings starting at $1,500.
Search Volvo S40 Questions
Volvo S40 Experts