close assist on the coupe - lessons learned

[snik]

hi guys

I was troubleshooting my passenger close assist on the coupe, thought I share some of my findings, and pick your brains about some other stuff

I have read Brett's excellent write up (Thanks B.), and here are some coupe specific differences

The Coupe pump does not have the air nipples for the back door at all .. They are sealed shut at the base from the factory. Also the wiring harness is different

Here is the harness colour code:

PINOUTS: (written at the back of the plug - numbered 1-10)
1 - blank
2 - YELLOW/WHITE - supposed to be for LR door (blank on the coupe)
3 - blank
4 - Green (LF door)
5 - BROWN/GREEN - Pneumatic Ctrl Module
6 - RED/YELLOW - Power (HOT when ignition on)
7 - BLUE - supposed to be for RR door (blank on the coupe)
8 - BLUE/YELLOW - RF door
9 - Black - Power (HOT at all times)
10 - BROWN - ground

there appears to be no wires for the trunk lid, trunk door handle microswitches going into this pump, although there are vac lines for it, so again I am not sure how it gets the electrical signal... and my trunk lid and handle soft close both work.

-------

now here's a doozy ..


my LF door (driver's) works well .. so I wanted to see how the microswitch behaves .. but there is no difference in continuity or voltage when door is open/shut

When I pulled the pump out of the trunk, I noticed that the RF vac line was severed .. fixed it and reset the fuse thinking my door would now work, but nothing .. the pump does not even run after the reset which makes me think it's the RF door microswitch. But there are only 2 door switches as far as I know ..

*one on the outside that controls the inside lights/annoying buzzer
*one inside that controls the windows dropping 0.5" when door is opened (and that works)

There is no change in continuity at the pump with the door opened/closed even on the door that works, so I am somewhat stumped s to how the pump knows the door is opened/closed???

any thoughts would be appreciated.

[syljua]

Originally Posted by snik

there appears to be no wires for the trunk lid, trunk door handle microswitches going into this pump, although there are vac lines for it, so again I am not sure how it gets the electrical signal... and my trunk lid and handle soft close both work.

Hi Snik,

The CL module gets the signal to pull the trunk from the PSE module (pin 5),
since also the handle retraction wants this information. Later years, either PSE or
CL (don not remember which) was given the responsibility of doing both actions.

Originally Posted by snik

There is no change in continuity at the pump with the door opened/closed even on the door that works, so I am somewhat stumped s to how the pump knows the door is opened/closed???

I'm quite certain, that the micro switch to tell the CL to take action,
is closed, only in the inner phase of the outer first closed position (understandable?).
A small time delay is put in the CL, so that is does not draw in a door,
thats slammed shut. The switch is again open in the fully shut state (same
as open door state).

br,
syljua

[snik]

thanks syljua, you are absolutely right .. just read your suggestion and tried it ..

fuse pulled and pump disabled

drivers door fully opened/clsoed - no continuity
partially closed (1st click) - there's continuity

passenger side - no continuity at any time

looks like it's a microswitch issue on the passenger side... but I have had the passenger side door panel off before, and there is only 1 microswitch inside the door lock mechanism which controls the windows dropping and shutting on the coupe. That is operational because while the door panel was off, I sat inside and triggered that switch manually and the windows would lift and seal and vice versa

I also have a spare passenger lock mechanism and there is only 1 microswitch on it (same one that controls the wiindows) .. so I dont exactly know what it is that I am supposed to replace

I have a faulty microswitch that does not exist

[syljua]

Originally Posted by snik

passenger side - no continuity at any time

looks like it's a microswitch issue on the passenger side...

Snik,

I have to moderate myself a bit. The signal to close the door, is present the second
position, not first, and non-present again in the third.

Where do you measure this. I guess, at the pump end?
I would try to measure it at the connector between door and door frame
as well. I do not have ETM here, so I cannot give you the correct pin, sorry,
but as I see from this thread we both participated in;
http://www.benzworld.org/forums/2108019-post17.html
the permanent signal of a closed door comes from micro switch S87s2,
and the non-permanent signal to close the door comes from S86s2 (got that
from WIS).

Now, this is for the left front door (same for sedan or coupe).
The same numbers for right door is;
S87s4 non-permanent signal to close right door;
http://www.classic-roadster.de/cgi-b...ITEM=S87%2F4x1

Lots of confusing part ID here, but I think
the easiest option, would to measure where the closing signal for left door is
on the connector between door and frame, and do the measurement for the
right door at the corresponding place. I think its best to remove the carpet on the
inside of the frame in front of the door, in the foot well.

Even if you looked at the inside of the door earlier, you may have to open
it up again. Also, remember to check the grounding of that switch.

br,
syljua

[Brett San Diego]

Thanks for the additional information regarding the coupe pump. "jvallet"'s pump shown in my write up is on his coupe, and it apparently works just fine. It looks like the usual sedan pump with 4 door outlets. Perhaps it is plug-and-play with using the sedan pump in a coupe, and a previous owner had swapped his out. I can't comment further since I have no experience.

Good luck tracking your problem. Looks like syljua has you covered.

Brett