smryab

Hi there all,

I have a bit of a problem with the 99 ML320. At this time that car will not start.

Let me start from the begining. The first time this happened the enging was turning but seemed there was no gasaline coming in. I took the Fuel Pump relay out and put it back in and the car started. One thing to not is it was 95 degrees outside and the car was parked in the sun. The same problem came back that night even though the temparature dropped a bit. I was able to fix it the same way. A little before this problem started few other things atarted happanning. The fuel guage was not working right most of the time. It would show empty after a fill up and then would start working again. Also, the trip computer (near the sunroof) stopped working all together. Will not turn on at all. Around the same time my radio stopped turning off when the key is removed. You have to turn the power off on the radio after you remove the car key.

To get back to the original problem, few days after the problem first appeared I took a trip of about 200 miles in another fine summer day (95 degrees). About an hour into the trip the car started overheating. I noticed that wehn I turned the AC off it would cool down again. As I was looking under the hood to see if there might be some other problems I could fix I saw that the AC fans in front of the radiator are not turning on even though it was very hot at that point (the car was showing 101 degrees outside) and the AC was blowing full strength. Since than, I never saw the fans working. Seems they do not turn on at all! Needless to say that engine compartment gets extremly hot. When the car will not start again and I try to feel the relays in the Fuse Box it feels like the relays have been cooked in the oven. It seems that after the car cools down again it starts again but not always.

I took the fuse box apart today after disconnecting the battery in hopes of finding some obvious problems but all the wiring and contact seem to be good. There were no signs of rust anywhere around the box. To add insult to injury after I assembled the box and connected the battery back the BAS/ESP light came on!

I check the for any codes with OBD scanner and found none. At this point I would like to get some advice from you guys before I take it to a mechanic...

Any help is greatly apreciated.

Thanks

Steve

Wolfgang

Welcome to mbworld.

1. Check fuse F10.
2. Check fuse F44. Might require upgraded harness.
3. Check crankshaft position sensor (CPS).
4. Crank steering wheel all the way to the left, then right to recalibrate ESP. That should be in your manual.

More info:
http://www.whnet.com/4x4/shoptalk.html
http://www.mercedesshop.com/Wikka/M112M113CPS

deutscheramg

:Jaws theme music....:
BEFORE 02 ML ELECTRICAL DISORDERS!!!
AAHHH!
sorry

00ML430 Bulldog

Sound like the symptoms of a defective Crankshaft position sensor. It tends to act up in extreme temperatures. It also does not log a fault code when defective.

nsfkid

The fuel pump relay can be a problem, I had the same problem. Change the fuel pump relay with the horn relay and see if the problem reappears. (The horn relay and the fuel pump relay are the same) If you look at the terminals on the fuel pump relay, check for any signs of discoloration which are an indicator the the relay is overheating. (Mine showed discoloration & the side of it was slightly melted, wiggling it would make it work temporarly. Just buy another relay about $12 at the dealer.
You can just have a bad relay, but this can also be a sign of high current draw from the fuel pump which occurs when the fuel filter is blocked or the pump is on its way out.

Mike.