Moderator note, June 20, 2025:
See post 31 for limit switch replacement item.
--- Pizzaguy

Please don’t hurt me for even asking this. I just acquired a 2007 Roadster Limited with 17k miles. It has the typical rogue, erratic, demon-possessed rear spoiler, which goes up nicely at 62 but won’t retract automatically or otherwise unless car is put thru another ignition cycle.
I have replaced the BCM, performed every known test on a brand new battery, cleaned ground contacts, and added an engine ground. There are no other glitches in the car - everything else is working correctly.
I admit I have not read every post on this, but I have read a lot of them and I don’t believe I ever saw a “final solution” to the problem outside of battery. Issues. Could someone save me some effort and advise how the spoiler issue finally washed out?

 

Have you tried an OBD scanner on your car. You might have a bad speed sensor.
If you don't have a scanner you can take it to Autozone or some other big store and they will scan your car for free.
If it doesn't scan as a Crossfire, enter it as a Mercedes-Benz SLK 320.
Let us know what you find out.
BTW, don't be afraid to ask any questions here.

 

.


Have you downloaded the factory service manual? It is a free download (including many other fixes that members have posted). Besides John's speed sensor issue in post 2, try this one. My uneducated guess would possibly be a spoiler limit switch issue. Anyway, check any spoiler problem located in the service manual, but you'll have to download it and peruse anything mentioning 'spoiler'.


.

 

First off, thanks to those who replied to my gosh awful redundant question. I read and react to all.
I have not solved the issue, but I have confirmed that the spoiler operation is definitely an every other ignition cycle phenomenon. Spoiler will work semi-correctly on one cycle but totally incorrectly on the next. That fact must have some significance.
Of even more interest is the fact that I discovered one of the limit switches had pulled apart and was hanging by its wires. I had no way of telling if all of the switch was there. Nevertheless, I put it back together but it made no difference.
One of you mentioned speed sensors - how can I obtain the correct ones?
Limit switches - how can I obtain those?

 

FIrst, STOP and take time to understand how it works.

The "wing" is operated by the Body Control Module, based on information the Brake Controller provides. The four wheel speed sensors feed data to the Brake Controller and the Brake Controller tells the BCM what the vehicle speed is. Any issue with this data and the wing will default to UP because the BCM does not know for sure what speed you are traveling at.

Additionally, erratic DC power to the Brake Controller or BCM will also result in a deployed wing; it seems you have addressed this.

In cars that are convertibles, an erratic wing combined with a convertible top that won't move tell you that there is nothing wrong with either system and that the issue is in the Brake Controller or CLP/SSM (Central Locking Pump/Security System Module).

The various systems in the car interact with one another. THis may not be a "wing" issue at all.

Given what you have posted, I'd yank the CLP/SSM out of the cavity in the trunk area, pull it out of it's insulative blanket, and look for water intrusion or corrosion. Yank out EVERY electrical connector and look for dampness or corrosion. If you find any, toss the CLP/SSM in the trash, go find a used replacement, and get the last 2-3 feet of the wiring harness. Replace the CLP/SSM and the last 2-3 feet of wiring, including all connectors, and you should be OK.

If there is no water damage to the CLP/SSM, report back and we can go from there.

 

Haven’t forgotten you; still pursuing this.

 

I don't see where you replaced the RCM, that is the first thing to do for spoiler, lights flashing no start, and stall at red light.
it may not be that but that is the first thing you should do.. you do have a spare RCM in your trunk right.

 

No spare RCM……bonkers spoiler is my one and only issue. All else works.
Could RCM still be bad?

Paul Brown

 

I never owned a limited so not 100% sure but from all i have read Yes the RCN is the blood or the crossfire
I have two spares with me at all times,, a few years back i was at the track ,,big race and my car died 1/2 way down the track
costed to end of track, replaced my rcm, ran the guy again and won. I have two friends and both as myself, we have a
RCM and both cam and crank sensors spares in the trunk. so yes get a spare RCM try it in the car if it does not fix it at least you now will have a spare jim

 

I think you are right. I already have a a spare BCM, why not get the RCM and be ready.

Paul

 

Well, you asked for a report….today I unearthed the CLP/SSM and it was as dry and pristine as the day it was installed.
Spoiler continues to operate semi-correctly only every other ignition cycle - I gotta believe that’s significant.

Any more suggestions? All appreciated.

Paul Brown

 

have U swapped the RCM yet instructions here do yourself a favor replace it don't try to repair it just send it it TJ.
https://www.crossfireforum.org/forum...-no-start.html

 

amx1397…

I’M a little confused. RCM problems seem to manifest themselves in starting issues. My issue is a erratic spoiler.

I will pull and inspect RCM today. I am very good at micro soldering, so if that is required, I can do it.

 

Did you see my reply re: CLP/ssm ?

 

It is very hard to diagnose a car based only on what someone types on a message board. The very attempt is full of pitfalls and misunderstandings, again, based on the idea of troubleshooting a complex electro-mechanical system based on text on a message board - we can only do so much. SO:

First, owning a Crossfire without having a spare RCM is a mistake. Order one, put it in, and see what you have - you MUST have a spare in the trunk at all times or risk being towed home someday.
THey plug in and can be replaced WITHOUT TOOLS or any real skill set.

Second, if the car's battery is over 48 months old, if the battery cable clamps look horrible or are loose - FIX THAT.

Third, if you have not done James' mod, do it today:
https://www.crossfireforum.org/forum...le-engine.html

If the problem persists, we can go from there.

 

Solder joints are not the only potential issue with an RCM. The relays also go bad.

 

that is what i have been saying without saying it, and Tj Has a test bench set up that we (Members) do no have.
I use to build aircraft circuit boards, for 8 years, now I no longer own a iron or pin to solder anything, i send
my RCM to TJ. I have seen as many as ten members say they soldered their RCM but it failed again,
and , we say send it to TJ but if you do have a spare RCM U could try iy as the RCM as i have said for about 10
years now the RCM is the blood of crossfire , Good luck and let us know when and how your car was fixed.
enough of my babbling ,,, jim

 

To All….. thought at this point, since I have received and followed up on so many good replies, a short recap of what I have done is in order.

Battery……brand new and no defects
CLP/SSM…..bone dry and pristine, no corrosion ever
RCM…..appears as new, no detectable cracked joints, relay armatures move freely
BCM…..replaced with another unit with no detectable difference in spoiler operation
Jim’s modification……..performed yesterday but have not road tested

I will be installing a new RCM to ensure old one is really good.
Will advise all of you in a few days

Many Thanks
Paul

 

Some DTC will not set the first or even second time; It takes more than one drive cycle to set the DTC.
You need to get a good scan of your car that will get into the manufactures diagnostics. It will point you in the right direction. Guessing at problems with only symptoms is a long and expensive way to fix a problem. Their are post on this forum as to good rather inexpensive scan tools that will work on the Crossfire, or go to an independent European garage/shop and have them scan your car: it will scan as an 2003 Mercedes SLK 320 R170. Hopefully that will help. Also be certain to down load the service manual as previous mentioned and read through the troubleshooting, you will need a volt/ohm multimeter as a minimum. Good Luck!

 

Gotta be RCM or Brake Controller. I can't see where else we can go with this.
One thing, (it's a long thread) - coupe or roadster? See, Roadsters whose top won't go up/down combined with a wing that has it's own mind points to CLP/SSM or brake controller.
The coupe is a pain, cause we have no convertible top to test with. Fact is, a top that won't move can be a problem, but it also can be a diagnostic tool, one that is denied us in the coupe.

To restate it: Not EVERY thing wrong with the car is a separate failure, sometimes, additional failed items/features are CLUES to what is going on.