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· Registered
1997 CL500
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1,436 Posts
Discussion Starter · #1 · (Edited)
Lumber support issue and passenger side mirror issue

I have noticed that lately the lumber support starts to inflate and deflate itself numerous times while i drive an also that the up/down passenger side mirror adjustment has stopped working. The right/left adjustment works, and the folding in and out of the mirrors work also. The driver side mirror works well with all the functions. What could be the problem ?
Thank you.
 

· Registered
95 S500
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159 Posts
Since your car is 97 MY, I am not 100% sure but.. you might have issues in the passenger side mirror wiring.
Mine is a 95 and the wires were a mess. It affected my steering wheel adjustment (only up and downs were working not in and out). Once I rebuilt the wires, the steering wheel adjustment was working too.
I believe all those functions are controlled by the convenience module.

I hope this halps.

2.7TT
 

· Registered
1994 S600 Coupe, 1995 S600 Coupe
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3,252 Posts
The module that controls the mirrors and steering wheel is not the convenience module in the trunk, but a separate module beneath the passenger side (LHD cars) forward footwells cover. You have to pull back the carpet from where it meets the fiewall and remove the aluminum plate underneath with runs from the floor to the underside of the dash
The controller has several relays in it which operate in matrix fashion depending on what steering column or mirror button is pressed. The operate either singly or in pairs. In my case, one direction of my steering column didn't work. I removed the module, and then it's cover, and plugged it back in. I actuated all of the switch directions until I found one relay that wasn't operating at all. Upon closer inspection, I found a very small indication that a drop of moisture had gotten in (how, I have no idea), and corroded one of the traces on the circuit board. I jumpered the break, and everything works again. Take off the aluminum plate I mentioned, and operate the steering column or mirror controls. You'll hear the relays clicking, so it's easy to ID the module.

The lumbar bladder is controlled pneumatically. It sounds like you have a leak in a line running to the bladder, or in the bladder itself. So it sounds like the PSE pump is cycling periodically, refilling the bladder. You need to trace the pressure lines, and test them for leaks.
.

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· Registered
95 S500
Joined
·
159 Posts
The module that controls the mirrors and steering wheel is not the convenience module in the trunk, but a separate module beneath the passenger side (LHD cars) forward footwells cover. You have to pull back the carpet from where it meets the fiewall and remove the aluminum plate underneath with runs from the floor to the underside of the dash
The controller has several relays in it which operate in matrix fashion depending on what steering column or mirror button is pressed. The operate either singly or in pairs. In my case, one direction of my steering column didn't work. I removed the module, and then it's cover, and plugged it back in. I actuated all of the switch directions until I found one relay that wasn't operating at all. Upon closer inspection, I found a very small indication that a drop of moisture had gotten in (how, I have no idea), and corroded one of the traces on the circuit board. I jumpered the break, and everything works again. Take off the aluminum plate I mentioned, and operate the steering column or mirror controls. You'll hear the relays clicking, so it's easy to ID the module.

The lumbar bladder is controlled pneumatically. It sounds like you have a leak in a line running to the bladder, or in the bladder itself. So it sounds like the PSE pump is cycling periodically, refilling the bladder. You need to trace the pressure lines, and test them for leaks.
.

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jal1224,
thanks for the detailed explanation of the convenience module.
I learn one more thing today...^^ :laugh

NewyorkS600,
Sorry to confuse you with incorrect information.

Thanks.
2.7TT
 

· Registered
1994 S600 Coupe, 1995 S600 Coupe
Joined
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3,252 Posts
It's not that complex. The fact that everything else works makes the job easier. Make sure you hear relays clicking when you try the up/down movement of the passenger mirror. If you don't, it could be the switch, the wiring between the switch and the module, or the module itself. If you do hear relays clicking, it is the wiring between the module and mirror motor, or the motor itself, or one of the connectors in that circuit.
Use the online version of Starfinder for circuit diagrams to trace wiring with. There is a link in one of the stickies at the top of this forum.

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· Registered
2002 E55 AMG Sedan
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1,434 Posts
Make sure you turn the dial to zero for the lumbar adjustment. Otherwise you risk causing an error code which will prevent the PSE from inflating both seats. The code can only be cleared through the 38-pin port. Or the motor in the PSE pump which supplies air to the seats will burn out and then you have a much bigger problem.
 
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