Aloha,

Okay so I have a 2000 volvo s40 1.9T with 110,000 miles on it. There is couple issues that im trying to troubleshoot. Car works great then at 4,000rpm it gets some sort of rev limited.

1st. Engine component fuse blows as soon as i start the car. What does this fuse go to? I think that may lead to fixing some CEL codes.

2nd. what are some sensors that would send a ecu to go in a sort of limp mode at that rpm.

3rd. driver low beam headlight doesn't work. Bulb was changed i haven't really tried to traced this yet. Kinda tempted to make my own circuit and avoid messing with the CEM box. I did check fuses and swapped and still didn't work.

I had 7 codes. its basically consisted of wastegate sensor, idle control sensor, and some evap crap. my guess some is probably linked to the fuse going out. so if i can figure what it goes to then maybe i can start testing sensors and wires linked to this. I do have a haynes manual but is useless as this fuse isnt even show in the wiring diagram.

please leave your input.

 

Get the VMWare version of VIDA for exploded parts views and electrical diagrams.

http://www.matthewsvolvosite.com/for...ic.php?t=55027

Since you mentioned the CEM I guess you know about the relay burning out for the low beam? Here is a thread with part numbers should you go that route.

https://volvoforums.com/forum/volvo-...w-beams-68391/

 

I was able afterwards trace the issue to the cem for the lights. I had 12v but as soon as I put a light bulb I had no power. I ended up just jumping another relay with using the passenger side headlight to activate it and avoiding changing or messing with the cem.

I will defintatly check out the links though. Thank you