20 Most Recent 2000 Volvo S40 - Page 8 Questions & Answers

You may want to change the idle control valve

When the battery was disconnected the computer lost it memory and it has to be programed with a Volvo Scan tool. There are other computer relearn procedures for vehicle or system operation. These may include:

Initial control unit programing

Traction control yaw sensor initializing

Multiplex communication

Anti-theft system or engine immobilizer system passwords

Volvo still won

check the fuse box to see if the fuse for the sunroof operates anything else if not just pull out the fuse

open the harness you damaged and repair the wires, then see how it acts

try to clean with spray no rubbing ,could be break cleaner.fuel filter maybe dirty.check air filter.vacuum leak.

check all fluids and emissions controlls..

ok everyone not trying to be unappreciative of your input and ideas however only w couple of you are even looking in the right area. generaly when your check engine light comes on its telling you your car is misfiring (obviously). its basically a caution light not so much a stop pull over and run type of light. yes you can damage your cat over a prolonged amount of time with no repair. so my thoughts on this are that is has to be the ignition coils. I drive a 90 vw and a 96 monte carlo. i just recently had this issue with my monte and first thing i did was replace the coil packs (ignition coils). result...light went out and not flashing or anything and perfermance is restored, all is well and it runs great. give that a shot, im 98% sure that will take care of your problem, and in your s40 there should be 2 coil packs, typically only one is bad but im that type of guy who doesnt wanna worry about the other one at all so i just replaced them all. they're typically around $50 each. my monte was $36 for 1 and there are 3. your s40 will only have 2 and there located directly under the plastic cover on top of the motor. hope this helps, good luck and dont waste your time searching in the wrong placed, check engine lights are usually sensors of an ignition misfire so if your not sure which one then just limp the car down to autozone and have them plug it in for free.

The humming is the fuel pump still on while vehicle is off,did someone work on your car recently,cos this sounds like symptoms of a fuel pump that has been connected directly.

Is the engine light on? How do you know that is the fuel running?Could be the radio antenna motor?

cheeck heater fuse

Most trailers have three circuits that you'll connect to your vehicle. One operates the taillights, one runs the left brake etc----------------------------------------------------------------------------------auto diagnostic tools