POWER DOOR LOCKS WORK WHEN THEY WANT TO
Thread Starter
Junior Member
Joined: Jan 2020
Posts: 23
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C202
POWER DOOR LOCKS WORK WHEN THEY WANT TO
My power door locks work when they want to. If I don't drive the car for a day and take it down the road. When I push the door lock button inside the locks dont work as I'm driving..
If I park the car and push the remote outside of the car. They lock very slow. How do I trouble shoot this.
If I park the car and push the remote outside of the car. They lock very slow. How do I trouble shoot this.
Member
Joined: Sep 2019
Posts: 119
Likes: 56
From: SD
2000 C230 - 2001 E430 - 2003 E320 -
The locks work on a vacuum system and the pump providing the vacuum is in the trunk passenger side. The pump has a value block that distributes the vacuum to every lock and other optional features. Given all the locks have this issue either you have a general slow leak or your pump is going bad (expensive) There are a number of threads related to this, but it all comes down to determining if you have a leak in a line or component or if the pump is bad. You can even have a leak in the pump/valve body itself. There are a number of low cost vacuum test tools - amazon, HF, etc, that will let you pull a vacuum on a section on line and see if it can hold a vacuum for a time period allowing to you determine if there is a leak/lock issue or if you have a pump issue. The WIS gives a complicated step by step procedure to isolate those kinds of issue. If you replace the pump you will need access to a MB HHT level tool to program the features into the new pump and it uses the big round connector located under the front hood on the passenger side by the firewall.
Search the w202 forums for vacuum pump, door locks, etc and you will find some really good info including folks that have done mods to the pump to help reduce heat and even folks that have completely taken apart the pump/valve body and repaired internal leaks in the plastic (a lot of work). The sad news is if you don't have the ability or time to do the work yourself - it can get very expensive.
Attached is from the EPC showing a general layout of the vacuum system. The distributor block (68) is built into the pump after 1997.
But there is one thing you can try. In the trunk, disconnect the negative battery and keep it off for 30 mins, and then reconnect it.This will give the CPU's a good old fashion reboot - maybe you will get lucky.
Search the w202 forums for vacuum pump, door locks, etc and you will find some really good info including folks that have done mods to the pump to help reduce heat and even folks that have completely taken apart the pump/valve body and repaired internal leaks in the plastic (a lot of work). The sad news is if you don't have the ability or time to do the work yourself - it can get very expensive.
Attached is from the EPC showing a general layout of the vacuum system. The distributor block (68) is built into the pump after 1997.
But there is one thing you can try. In the trunk, disconnect the negative battery and keep it off for 30 mins, and then reconnect it.This will give the CPU's a good old fashion reboot - maybe you will get lucky.
Last edited by tyabnet; Feb 3, 2020 at 07:20 PM.
Thread Starter
Junior Member
Joined: Jan 2020
Posts: 23
Likes: 0
C202
I hear the pump work when I lock or unlock the doors. Seems to be ok. Crazy thing is. When I moved the pump out and started to inspect it. I pushed the door lock button by remote. he locks started to work much better.
I took a air hose and blew the dust off it. It has worked since. Could be a slow leak or a glitch in the pump. Who knows.
Thanks again for your reply! We see if it last.
I took a air hose and blew the dust off it. It has worked since. Could be a slow leak or a glitch in the pump. Who knows.
Thanks again for your reply! We see if it last.
Junior Member
Joined: Dec 2019
Posts: 39
Likes: 0
C-220
My power door locks work when they want to. If I don't drive the car for a day and take it down the road. When I push the door lock button inside the locks dont work as I'm driving..
If I park the car and push the remote outside of the car. They lock very slow. How do I trouble shoot this.
If I park the car and push the remote outside of the car. They lock very slow. How do I trouble shoot this.
Newbie
Joined: Mar 2021
Posts: 1
Likes: 0
Mercedes w202 C200 Elegance
The locks work on a vacuum system and the pump providing the vacuum is in the trunk passenger side. The pump has a value block that distributes the vacuum to every lock and other optional features. Given all the locks have this issue either you have a general slow leak or your pump is going bad (expensive) There are a number of threads related to this, but it all comes down to determining if you have a leak in a line or component or if the pump is bad. You can even have a leak in the pump/valve body itself. There are a number of low cost vacuum test tools - amazon, HF, etc, that will let you pull a vacuum on a section on line and see if it can hold a vacuum for a time period allowing to you determine if there is a leak/lock issue or if you have a pump issue. The WIS gives a complicated step by step procedure to isolate those kinds of issue. If you replace the pump you will need access to a MB HHT level tool to program the features into the new pump and it uses the big round connector located under the front hood on the passenger side by the firewall.
Search the w202 forums for vacuum pump, door locks, etc and you will find some really good info including folks that have done mods to the pump to help reduce heat and even folks that have completely taken apart the pump/valve body and repaired internal leaks in the plastic (a lot of work). The sad news is if you don't have the ability or time to do the work yourself - it can get very expensive.
Attached is from the EPC showing a general layout of the vacuum system. The distributor block (68) is built into the pump after 1997.
But there is one thing you can try. In the trunk, disconnect the negative battery and keep it off for 30 mins, and then reconnect it.This will give the CPU's a good old fashion reboot - maybe you will get lucky.
Search the w202 forums for vacuum pump, door locks, etc and you will find some really good info including folks that have done mods to the pump to help reduce heat and even folks that have completely taken apart the pump/valve body and repaired internal leaks in the plastic (a lot of work). The sad news is if you don't have the ability or time to do the work yourself - it can get very expensive.
Attached is from the EPC showing a general layout of the vacuum system. The distributor block (68) is built into the pump after 1997.
But there is one thing you can try. In the trunk, disconnect the negative battery and keep it off for 30 mins, and then reconnect it.This will give the CPU's a good old fashion reboot - maybe you will get lucky.
Attached photo of vehicle.
W202 Mercedes C200 Elegance
