feras said:
hi guys... has anyone got an idea about the cruise control ? where is the control unit ? mine is 1990 sl500 and the cruise control not working at any speed. i tryed to find information about the system in all data but nothing about the cruise control. please if anyone got an idea about this system reply to me.
Hey....
I have the same - 1990 500SL.
Not sure why you can't find the info on ALLDATADIY. I just looked it up and there is soem info available (link for cruise control on the first page after you log onto to the car's info).
It's got some info - but doesn't really tell you much about where to locate the control unit (if it has one). There is something about ASR and Cruise Control Amplifier (Cruise Control Inoperative After Amplifier Replacement).
I did however find this info: "The coding plug is connected to the control unit. On 190D and E models, the control unit is attached to a plate located in the right hand front foot well. On all other models, the control unit is located under the left hand side of the instrument panel. While compressing coding plug locking lugs, disconnect coding plug from control unit."
There are some diagrams (under cruise control module) for the location of:
Locations
. CC/ISC Control Module
. EA/CC/ISC Control Module
I am guessing CC = Cruise Control. The location for these are under the hood - passenger side top corner (US model) closest to the side mirror. It shows 5 small rectangular units. The digram has arrows pointing to the units with labels such as "N4/1", "N3/2" .. etc. To be honest I have no idea what they are.
Some more info i just found on ALLDATA for 500SL (90):
Control Unit Service and Repair
Disable airbag system, refer to MAINTENANCE PROCEDURES/AIRBAG ARMING & DISARMING.
Remove left hand side instrument panel undercover, if equipped.
Disconnect electrical connector from control unit.
Remove control unit to pedal bracket attaching screws, then remove control unit.
Reverse procedure to install.
ASR unit is located same area I mentioned before. Not sure if they are labelled on the car itself... but on the diagram they are:
Component Name ASD control module (in Module Box) - Component ID N30/2
..................................................................
It all looks a bit too complicated to me. So, if you are not autoelectric-mechanically inclined, you may need to see someone else to have it fixed properly.
I also read somewhere on here that the cruise control system is very sensitive to the type of break lights on the car. If they are different to OEM, then the cruise stops functioning. I think it has something to do with the cruise being linked to the break lights and the breaking system. Not entirely sure... but worth finding out.
Hope that helps!
Over out...
Sapps