99 E430. Tried to unlock door not working. Open it with valet key. Car starts. No power seats. Check fuses, ok. Seats work now. Garage door opener not working. no red light. Remote battery good. Everything else works.
Remote and homelink not working. Please help.

 

check health of car battery. check fluid level, specific gravity, voltage under load

 

Thanks! I just unplug the battery terminal and everything went back to normal. Wondering what happen?

 

not uncommon for loose terminal to build up resistance, especially during winter
when metals contract and all. it may not feel 'loose' to you, but electrically
speaking, it can be on the low side of metal-to-metal contact.

 

If convenience items start acting up again over the next week or so, and your battery is good on all counts, you probably have a CAN-BUS problem. If so, just wheelbarrow money to your nearest dealer. Disconnect/reconnect of the battery will "reboot" the system and all should work until incorrect voltage from the offending module starts affecting the system again.

 

Its back again. Now my driver side window wont work. Along with remote and homelink.

 

Have the battery check out (be sure it hold charge), if it does, test the alternator, be sure it's good. The gremlins (my own experience) point to the weak battery, if it's a few year old, replace the battery may cure it all.

 

Thank you. I'll have it check tommorow. You mat be correct. Thanks.

 

Check battery.Its ok. Happen again today. Evwn dome lights is out.

 

Just wondering how it starts right up if the battery is on its way out.

 

b/c the CAN-BUS works on very small voltage, 1.3v to 4.7v or something, so if the battery isn't perfect, the voltage can vary too much. The reason different items go each time is that they are all tied to the same BUS bar, so the brain may see the wrong voltage from a different module each time.

I keep an 11mm rachet under the rear floor mat and use the handy battery cable disconnect on the passenger side, behind where the rear passenger legs would be. Keeps you from having to remove the seat, which sucks with a child seat. Once a week I "reboot" the car to have everything function again for several days.

 

Just replace my battery tonight. I got one from the dealer for $170.00
Let see what happens. I hope that will solve the problem.

 

It did not solve the problem. It happen again today. Dont know what to do. I cant just keep unpluging the battery every time it happens.

 

all the fuses and relays in the conv. module box under the hood or did you just check the fuses under the seat and in the flap along side the steering wheel just inside the door?

 

ah....prompts me to suggest that you check beneath the rear seat for signs
of water intrusion....which would really mess up (inconsistently so) electrical
and pneumatic functions

 

Just went to two shop to diagnose my car, they coudnt find whats wrong with my car. Its very frustrating. Car is running great. Its just this electrical gremlins.

 

How do you check control module?

 

I noticed the area under the seat where the battery is wet. Now, it got worse. Even though I reset the battery, the windows dont work. I'm so frustrated with this problem. I went to 8 different shops. One told me to get new ECU.

 

It's one component on the CAN bus. If you have water near the battery, could well be that the PSE is the culprit. Given the cost of the components, guessing is a risky proposition. I would look for a shop that says they can diagnose CAN bus problems, and pay them to isolate the faulty unit. You can probably do the replacing yourself.

 

Do you think my aftermarket headunit is the problem. They may wire it wrong. It only happen after I change it. Maybe a ground?

 

Probably not. With most headunit installations a patch cord is used to route the signals from the connector on the wiring harness to the radio being installed. Since those connections are dedicated to the radio/changer not much chance that there would be interference other than with the radio itself. A ground fault would probably mean a discharged battery which doesn't seem to be your problem.

As others have mentioned, all your symptoms point to a problem with wiring around the rear seat fuse panel and/or the PSE pump operation. The fact that you found water collecting in that area is a big RED flag. It sounds like you had a dealer install a new battery so I'm surprised that they didn't notice or call that to your attention.

Along the edge of the car under the doors look for two water drain points. They look like rubber grommets about 3/4" in diameter. On the E320 wagon they are just behind the front wheel housing and just in front of the rear wheel housing. However, I think the rear ones may be behind the rear wheels on some models. Check to make sure they are not plugged with debris. Especially the one closest to the battery area.

 

Thank you so much. I check it and its dry. Next will be my driver side seat and window control module. Those two are the first two that goes out every time I reset the battery. I unplug the seat today. Will see.

 

Would this work with w210?

 

I went to a friend that work in a benz dealer that has star diagnostic in his his laptop. Its showing no communication in the driver door control module and over head control module. Should I change dcm or both? I saw a used dcm in ebay for $95.00 He wants $200.00 for labor. Any advice please.

 

I don't know how handy you are but removing the door panel is pretty easy. Just ordinary fasteners. Search this forum or detailed directions on peachparts and benzworld W210 sites. If you could tackle it yourself you could use the savings to afford a new controller.