My 2006 roadster suddenly has the spoiler light flashing all the time. Spoiler is down, but wont go up using the button.

Battery is good, fuses good, Tried ESP reset, etc I have found threads with the spoiler stuck up, but not down. Any ideas please?

 

From the schematic, I'd say fuse, switch, limit switches, wiring, BCM or motor :

 

Ala Xfire is on the right track here. Your Computer is telling you that some element is not in proper condition for you to be driving and allowing the spoiler to deploy.


Truck lid not closed (sensor off) or the spoiler is not registering as in mode proper for thespeed you are traveling.

I say most likly one of the many limit switches.

Try a battery disconnect before anything else to reset the programs.

 

Does your top go up and down? If it refuses as well, I'd say the switch(s) that tells the BCM the trunk lid is closed is bad.
An open trunk indication causes the top AND wing to be disabled.

 

The most common problem for the flashing light is an open circuit in the spoiler motor. The BCM is looking for a certain amount of resistance in the motor circuit and can't find it.

 

thanks guys. So far, tried battery reset, no change, opened rear bootlid - motor looks ok, top wont go down no spoiler movement.

Where is the "lid not closed" sensor?/ limit switches? in the boot? cant see it, except for a small micro switch in the spoiler motor gearing. is that it?

Next I will take the motor off and test it out of the car. Also say the fact that the BCM can have bad solder joints ? Might look at that next.

This did happen once, a couple of years a go. I took the ECU out, put it in a hot dry area for a couple of days (airing cupboard)
put it all back and it worked for another year. ECU was tested ok, but this fix seemed to work. Perhaps it jolted the BCM when I took it out and replaced it? Or a red herring.

Looks like a fun weekend to come!

 

The bad solder joints are particular to the RCM, not the BCM.
The trunk ( boot ) microswitch is inside the latch mechanism.
The limit switches are in the spoiler mechanism.

Good luck !

 

Yea, if the top won't move either, then I'd say the trunk lid is not indicating that it is closed.

I have TRIED to figure out where that sensor is - Ala_x, can you point in the manual to where it is? That is the one sensor I've never been able to find.

Also, downloading and printing the specific pages in the manual will help you figure this out. But again, if neither the top or spoiler will move, the most likely common denominator is the sensor that indicates the trunk is closed.

 

To be quite honest, that was an assumption.
I looked thru all the parts pdf's and the location pdf and can't see anything.
I will take a look tomorrow at the trunk latch assembly and see what I can find.

 

Mark, the switch IS in the latch mechanism, here's pictures :

 

thanks guys, I will give it a try and report back!

 

NOTE: When I unplug the connector to the latch switch, the cargo light goes out.
This means the switch is closed with trunk open, open with trunk closed.

 

Yea, so yank the connector out and if the top and spoiler work, you need a new switch.


(Just be prepared for them to tell you the "switch, latch and harness are one assembly and must be replaced together" for a cost of half a week's pay.

 

The switch is mounted to the latch with miniature spring-clip thingeys ( see picture 3 above ), won't be easy, but with a bit of fiddlin I think it possible to replace the switch.
You should be able to find a switch from Mouser.

 

Yea, Mouser or Digi-Key - between the two, I think you can buy ANY switch made. (Also, any capacitor or any non-microprocessor I.C. chip as well. Not to mention thousands of weird electronic parts and assemblies.)

 

The part that hold it in place is often called a push nut, although this one consists of two nuts in one.

OP
Look at the switch, ignore the Mercedes logo and number and look for a manufacturer and their number. You can be quite certain they do not make this part just for Mercedes. Google that part number.
If push comes to shove try and take this one apart and see what ails it, maybe you can mend it.

 

Guys. Remember me? Still trying to fix this. Haven't had the need as it's been raining in England for months! Anyway latest is:
Light flashing all the time, but spoiler goes up and down whilst driving at the right speeds. Won't go up or down via the dashboard switch. Roof won't go down. Disconnect battery wait a few mins, reconnect and everything works perfectly. Tried to stop it working as in opened the boot (trunk) switched off ignition, back on, top down, up etc, all fine. Left car with top up foe 10 mins with ign off, turned on ign, light flashing again and nothing works again! Didn't touch anything it just changed its mind! Getting very baffled now. Any ideas?

 

I know of several problems where the battery tested fine, yet it always ended up being the battery. Find somewhere that will let you test out a new battery and see if the problems repeat themselves. These cars are so finicky with the voltages that you never know.

 

Thanks, will try that.. I did have a similar problem with my BMW x5. All sorts of strange things like the sunroof wouldn't open, or close etc., a new battery fixed it 100%.

So worth a try. the battery is only 2 years old but still a fairly small cost to try it.

 

If you still have the X5 and the battery is newer, just swap them and see what happens.