Volvo S40 - Recent Questions, Troubleshooting & Support - Page 7

well that can be a pain to deal with down unda! Personally i think the traction control and the stumbles are not related. find out what the check engine light is, and go from there, could be as simple as a coil over, coil or set of plugs/wires or could be a gummed up throttle body, or vacuum leaks, check all the vaccum lines clean the throttle body test drive and , find the code and do some research and or post the code here and i will try to get back to you. a misfire code can be really helpful if it tells you which cylinder, if your over due for plugs just buckle down and replace them.i say dont throw parts at it because it might not help and get expensive, but cleaning the throttle body and checking vacuum lines, replacing plugs should be preventative maintenance in my book.use a throttle body cleaner can you can get a local parts store to clean out the throttle body. dont use carb cleaner as it could damage sensors, if your mind is stuck on the traction control and or you get the stumbling fixed start on that here :for the hard shifts check the transmission fluid for dark colors or burnt smells. then check out the motor mounts and trans mounts, but that should be done before moving onto the Traction control.anyways if you suspect the traction control start with checking all the abs sensors. can use a good scanner with live data to save you time and check to see if they are all giving you good readings.if no scanner is available you need to see if they can be removed from the hub, but be careful as they can break off inside. if they are removable from the hub check them for metal particles and make sure they arnt ground down on the ends, a bad hub will grind down the ends of them. if they look good then let me knowGood luck.

The layout should be printed on the fuse box cover.

Unless is was the one doing the testing I can not say that it will fix the problem. I would check the fuel pressure, the fact you have a rich code (P0172) means you may have excessive fuel pressure and the sensor is reading that.I assume this is a four or six cylinder and you have only one bank of cylinders. Check the fuel pressure before you do any parts replacing.

Did you remove the dist. while replacing the head if so you may have dropped the dist back in 1/2 tooth off on the timing and that would cause the engine to back fire. You need to bring #1 piston to the top of the cyl. and then make sure the rotor in the dist is pointing to #1 spark plug wire on the dist. cap and then drop the dist. You may need to turn the oil pump shaft to align the dist before dropping it onto the oil pump shaft. You can do that with a screw driver.

sounds like thats correct. fault camshaft position sensor or wiring to ecm is prob

Does the smoke smell like burnt antifreeze or motor oil?

Here's a guide that includes removing radio screen.

use a meter and test the connections ,lines ,pump for damage or short

Check CEM module.

Sounds like dirty battery terminals, make sure they are shiny clean. if ok see if the motor can be turned by hand , a clicking sound often points to the following dirty terminals, flat battery, stuck starter motor.

Most cars you can do without lifting engine make sure don't do anything wrong for nothing.

Clean throttle body before replacement, particularly sensor orifices.