Mercedes-Benz Forum banner

1 - 13 of 13 Posts

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #1
All adjustments on the passenger (right) seat of my 2000 E320 are dead - no clicking, no sound, nothing. The driver's seat, steering, mirror adjustments all work perfectly.

So far I have done the following:
1. Searched and read the forum.
2. Checked the fuses.
3. Disconnected the battery for 30 minutes.
4. Per STAR TekInfo confirmed that there is power to the seat ESA control module N32/2 and that the adjustment switches on the door illuminate.

I have not checked power to the door switches as the illumination works and I am reluctant to pull the panel. I do not have the means to read codes for this system.

So I am looking for suggestions on how to proceed? It seems possible that the seat's control module is kaput. I would swap it with the module from the working seat, but I cannot see a way to remove it. So guidance would be appreciated.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,719 Posts
What fuses have you checked ? ESA ? DCM ?

Do the memory function for the seat work ?
Does the window go up and down with the window button control ?
Does the right mirror control work ?
Does the IR key initiated function to roll down / up functions work for the passenger seat ?
 

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #3
mrboca, I checked the following fuses: front under hood: 16; under rear seat: 1, 8, 9, 13,
14.

The memory function did nothing. I assume any memory is now lost since I disconnected the battery.
All windows and mirrors work correctly from the center console, including the right side.
Opening/closing all windows and sunroof from the key remote works on the right side. Not sure if I understand your question here.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,719 Posts
Opening/closing all windows and sunroof from the key remote works on the right side. Not sure if I understand your question here.
That was to check if the passenger DCM can communicate with the other modules like SAM, and if the passenger window goes down and up with IR key activated convenience control (windows, sunroof). So it seems to be OK.

If the LEDs on the switch unit turn on with the headlight operation, that means the switch assembly receives power and grounding. The key depressions work on switching in ground in series with specific resistor values for each function (voltage coding), so if internally the ground trace is broken to ALL switches none of the buttons work. This seems to be a remote possibility. Usually one set of functions do not work due to switch issues.

The problem may be the ESA CANbus connection at the passenger door sill (X30/7 hub). The port number on that hub for passenger seat module (ESA) is 5. It is either checked visually or via a scanner that can access the ESA. There could also be a problem with at the seat side of the CANBus.

You need to remove the seat to access the ESA module. Make sure that it receives power, so there is no power / grounding wiring issue.
 

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #5
mrboca, thanks for sticking with this. I'm not sure of the location of the X30/7. I popped off the lower passenger sill and did not see anything obvious. If you can tell me how to access it I'll take a look. As I said, I don't have a scanner that can access the ESA.

I did unplug the connector at the module under the seat and confirmed 12V power/ground. Visually everything looks good. I also looked at AC voltages at the non-power connections and think that the canbus signaling is working, because I see consistent fluctuations when manipulating the seat switches.

So I am leaning towards the conclusion that the module under the seat is the culprit. I would just be nice to have more confidence before getting a new one and pulling the seat.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,719 Posts
On pin 6 of the connector 1 you should see 5V with the multimeter set to AC, as this is CANBus low side. There are two power inputs from two fuses.

I know the driver's seat can operate with either key is in position 1, or position 2 or when the door is open and key is not inserted. I believe for the passenger side, the key must be in pos 1 or pos 2. I am not 100% sure though.
 

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #7
I am not seeing 5VAC between pin 6 and any of the others. Otherwise I get various AC and DC voltages between combinations of the pins, some of which change when the seat adjustment switches are pressed, and whether the key is in position 1 or 2 or the door is open, or dormant. All readings taken the the connector unplugged.

HOWEVER, I do get DC voltages that match exactly to those specified on pages 36 and 49 of http://www.carlogic.org/bg/data/MB CAN(ICC).pdf for both low and high. In summary, there is 12V to the controller module, and I am confident it is getting Canbus signals.

My recollection is that the passenger side is the same as the driver's, which will work with the door open. But to be sure, I am testing with the key in position 1, or out to let it go dormant.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,719 Posts
Here is the diagnosis for N32/1 and /2. You can order the ESA module and see what happens when you replace it. Hopefully it will work. These are the issues that are hard to diagnose without a diagnostic tool.
 

Attachments

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #9
I've ordered a used module on eBay - fingers crossed. So be patient until it arrives next week. In the meantime I have to determine whether I can get the seat out without being able to move it. What a PITA!
 

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #10
Progress! The used control module I ordered on eBay arrived. Luckily, the seat was stuck in a middle position where I could access all four seat bolts and remove them. This allowed me simply to tilt the whole seat and rail and swap out the control module.

Lo and behold, all adjustment functions work... except fore and aft movement. There is a clicking noise when I try to move it forwards or backwards, so I think there is some other problem. I'll now do my due diligence to troubleshoot that.

In the meantime, all suggestions are welcome. Thank you, mrboca, for your help thus far.
 

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #11
So I tugged all the connectors, sprayed electrical contact cleaner, tried to look into the tracks, tilted the seat forward and back, to no avail. Then started swapping fuses 8 and 9 and movement! But not reproducible. Then I found the culprits pictured and now normal service has resumed and all is right with the world. I hope this is my last on the subject.

BTW, I found the dime in the back of the left seat track. I believe that tilting the seat dislodged it, and thereafter moving the seat may have pushed it out - not sure exactly.
2628218
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,719 Posts
Is this one of the fuses you switched around ?
Reminds me of the Avalon I had 20 years ago. The passenger seat would move backward, but when it moved forward all the way to the front, it would blow the fuse. I took the seat out and connected to a battery. It would move back and forth, no problem. Only had the problem when installed. Didn't have much time in my hands, and left it in mid-position, and pulled the fuse out. Rarely had a passenger anyway.
 

·
Registered
2008 E350 110k, 2000 E320 143k, 1983 380SEC 240k
Joined
·
951 Posts
Discussion Starter #13
Yes, this is one I switched previously, but it was not so obviously burned out at the time.
 
1 - 13 of 13 Posts
Top