Strange Issues
Thread Starter
Newbie
Joined: Sep 2007
Posts: 4
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1999 ML320
Strange Issues
Hey all, first post on the site. My wife has a '99 ML 320 that has had some strange issues over the last few weeks. First, the driver's window would go down but have trouble coming back up - when you held the switch, the window would go up about an inch, and that was it for about ten minutes and you'd just have to keep trying. It would take a couple hours to get it all the way back up (sometimes over the course of a few days). Then, the compass/fuel computer in the overhead console stopped working. About the same time, we noticed the radio would stay on when the car was completely off. This all seems electrical, so I checked the fuse panel, but don't really know what I'm doing. Any ideas?
To make matters worse, the check engine light came on three days ago. I doubt it's related to the other issues, but the engine is running fine. Tried disconnecting the battery but the light popped back on after a couple hours.
Thanks in advance for any insight or advice.
To make matters worse, the check engine light came on three days ago. I doubt it's related to the other issues, but the engine is running fine. Tried disconnecting the battery but the light popped back on after a couple hours.
Thanks in advance for any insight or advice.
Super Member
Joined: Aug 2007
Posts: 675
Likes: 1
From: LA, CA
2002 E55 AMG
Hey all, first post on the site. My wife has a '99 ML 320 that has had some strange issues over the last few weeks. First, the driver's window would go down but have trouble coming back up - when you held the switch, the window would go up about an inch, and that was it for about ten minutes and you'd just have to keep trying. It would take a couple hours to get it all the way back up (sometimes over the course of a few days). Then, the compass/fuel computer in the overhead console stopped working. About the same time, we noticed the radio would stay on when the car was completely off. This all seems electrical, so I checked the fuse panel, but don't really know what I'm doing. Any ideas?
To make matters worse, the check engine light came on three days ago. I doubt it's related to the other issues, but the engine is running fine. Tried disconnecting the battery but the light popped back on after a couple hours.
Thanks in advance for any insight or advice.
To make matters worse, the check engine light came on three days ago. I doubt it's related to the other issues, but the engine is running fine. Tried disconnecting the battery but the light popped back on after a couple hours.
Thanks in advance for any insight or advice.
1. Take the car to Autozone, borrow the OBDII scanner.
2. Under your dash there should be a plug for the scanner.
3. Plug it in (make sure the key is on the "ON" position)
4. Write down the codes the scanner gives you.
5. Come back to these forums, post the codes.
MBWorld Fanatic!
Joined: Jan 2007
Posts: 1,152
Likes: 29
From: Sydney, Australia
190D 2.5 (x2), 190E 2.6, W202 C240,W202 C43 (C55), W210 E55, W212 E250CDI
The window problem sounds like he windoe switch group is failing. Fairly common issue.
The radio and trip computer is probably a blown fuse (yes, the radio will stay on when the fuse blows, strange wiring)
The engine problem really needs an OBDII scanner to get the codes, no short cuts there
The radio and trip computer is probably a blown fuse (yes, the radio will stay on when the fuse blows, strange wiring)
The engine problem really needs an OBDII scanner to get the codes, no short cuts there
MBWorld Fanatic!
Joined: Sep 2005
Posts: 6,188
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From: Albuquerque
'10 CL550, '12 GL550
The window problem sounds like you've recently had a dead or disconnected battery.
The switches have two positions each for up and down.
Go to first postion only for up. When it gets there, hold it completely down (i.e. 2nd position) for a bit until the system learns where top is. Do same for down. Problem should be fixed until next time battery voltage is lost.
The switches have two positions each for up and down.
Go to first postion only for up. When it gets there, hold it completely down (i.e. 2nd position) for a bit until the system learns where top is. Do same for down. Problem should be fixed until next time battery voltage is lost.
Thread Starter
Newbie
Joined: Sep 2007
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1999 ML320
Thanks for the responses. Here's where I stand as of today. Tried the two-position window trick but didn't have any luck. I'm thinking it's a faulty switch, but then again, what do I know? Called the dealer and talked to a tech about all my issues just to see what he had to say. Of course, $120 to diagnose the engine light. Didn't give much insight into the overhead console and window issues, just that he could look at them. As far the radio, he said it's supposed to stay on until you take the key out and open the door. I couldn't remember if I'd actually tried opening the door, so I tried it later on and the radio still stayed on.
AutoZone said they don't have the right equipment to read my code, but suggested Aamco. So I went and the free diagnostic came back with a code saying the long-term fuel-air mixture was 27% richer than normal (he said it can vary between +/- 30% from the normal ratio for short periods, but over the long term should be near normal). The guy said it was probably a bad sensor, but he's checking it out this afternoon. He's also going to check my fuse for the radio/console issue.
I always worry about getting screwed by dishonest mechanics, but this guy seemed pretty straight and took a lot of time to explain the code to me. He's charging $95 for the detailed diagnostic, and then I'll have to decide on getting the work done.
Thoughts?
AutoZone said they don't have the right equipment to read my code, but suggested Aamco. So I went and the free diagnostic came back with a code saying the long-term fuel-air mixture was 27% richer than normal (he said it can vary between +/- 30% from the normal ratio for short periods, but over the long term should be near normal). The guy said it was probably a bad sensor, but he's checking it out this afternoon. He's also going to check my fuse for the radio/console issue.
I always worry about getting screwed by dishonest mechanics, but this guy seemed pretty straight and took a lot of time to explain the code to me. He's charging $95 for the detailed diagnostic, and then I'll have to decide on getting the work done.
Thoughts?
MBWorld Fanatic!
Joined: Jan 2007
Posts: 1,152
Likes: 29
From: Sydney, Australia
190D 2.5 (x2), 190E 2.6, W202 C240,W202 C43 (C55), W210 E55, W212 E250CDI
The engine light would most likely be the air mass meter failing.
The radio will be a blown fuse and the window problem will be the switch group failing
The radio will be a blown fuse and the window problem will be the switch group failing
Thread Starter
Newbie
Joined: Sep 2007
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1999 ML320
Aamco traced the check engine problem back to a bad MAP sensor. Parts and labor (incl. the diagnosis) was $370, so could've been much worse. When they started looking into the console/radio/window problem, they noticed many of the bolts holding the electric grounding wires to the frame of the car (mostly up near the firewall) were loose. They tightened them back up and the console came back on. The bad news is that this problem may have caused damage to the entire vehicle computer, so I'm crossing my fingers that it's okay. Of course, now I wonder of this was causing the check engine light as well, but oh well.
The radio problem is still there, but it's not a big deal so I'm probably going to ignore it for now. All the fuses were fine, so it's a mystery at this point. I agree the window is probably a bad switch (especially after reading that this is a common problem in the other forums), so I'm going to try to fix it myself. Sounds pretty easy to unscrew the wood panel and adjust/replace the switch.
The radio problem is still there, but it's not a big deal so I'm probably going to ignore it for now. All the fuses were fine, so it's a mystery at this point. I agree the window is probably a bad switch (especially after reading that this is a common problem in the other forums), so I'm going to try to fix it myself. Sounds pretty easy to unscrew the wood panel and adjust/replace the switch.
