R230 Sl350 20014 - remotes (RF) not working

[C a r s e]

I have the same problem, 2004 SL350, IR is fine, I have bought both RF modules that fit under the dash, but will try to get it on STAR somewhere first to see if there is a more obvious issue, although with the IR working to open the doors its looking like the RF amp - no issues with radio interference or anything like that - I'm in no rush to start stripping out my dash either, I have a copy of WIS, but can't find where the dash disassembly section is

Hi, I have the exact same issue as in this thread, did anyone manage to get a fix?


Symtoms:

• Keyless Entry/Start (KG) NOT Working - 'Key Not Recognised' appears on dashboard
• Remote Locking (RF) NOT Working - Cannot Lock/Unlock car at any distance
• Infrared Locking (IR) is Working, I am able to Lock/Unlock the car if I point the key(s) directly at the IR sensor(s) on the door handles (Where Boot, Doors and Petrol Cap all lock/unlock), which means the PSE pump is working.

So far I have:

1. Replaced main battery in boot
2. Charged Battery under bonnet (Was more or less already fully charged)
3. Replaced batteries in both key fobs
4. Checked all fuses (With 12v light tester)
5. Tried a couple of steps to sync the keys (Not sure if any of them were correct)
6. Connected to STAR, where there was no errors shown, however the '750 CGW. N93 (Central Gateway, Control unit)' was shown as 'NOT PRESENT' ??? (Not sure if this is normal or not)
7. Disconnected both batteries (overnight) in the hope a shutdown of the system resolved it
8. Unplugged all SAN connectors (Located behind drivers seat) one by one
9. Tested all other electrics in the car, everything else seems ok (including alarm).

The car is garaged most of the time, so cant be caused by a water leek (Boot and inside car is bone dry).

My first thought is what links the KG and RF systems, are the reliant on each other if so what components do they share? also is it possible to reset the KG and RF system(s)?

Thanks in advance

 

[C a r s e]

My car a 2003 SL55 (R230)

 

[Michelten]

In many cases these ilógical electrical problems (aka “Gremlins”) are the result of microfilm corrosion in connectors and crimped cable terminals - not surprising in vehicles 15yr old or greater, particularly if at some point they have been stationary under moist conditions for extended periods.
The fuses and related connectors to the CDL RF amplifier are situated in the compartment behind the driver seat. Open it, remove a cover plate, and pull all fuses and fit them again. Shake a bit the wiring harnesses and connectors and give a gentle push/pull/push to the cable bunches that go into the fuse terminas and connectors.
Try your KeyFOB then.

 

[C a r s e]

In many cases these ilógical electrical problems (aka “Gremlins”) are the result of microfilm corrosion in connectors and crimped cable terminals - not surprising in vehicles 15yr old or greater, particularly if at some point they have been stationary under moist conditions for extended periods.
The fuses and related connectors to the CDL RF amplifier are situated in the compartment behind the driver seat. Open it, remove a cover plate, and pull all fuses and fit them again. Shake a bit the wiring harnesses and connectors and give a gentle push/pull/push to the cable bunches that go into the fuse terminas and connectors.
Try your KeyFOB then.

Thanks Michelten,

Will disconnect both my batteries and give this a shot

I take it you have never had any issues with your locking ever since?

Your symptoms sounded very much like mine, only being able to lock/unlock car via IR sensor on the door handle.

 

[Michelten]

Yes, the problem was similar: only infrared left door would work.
This procedure took the problem away and it hasn’t ocurred again ever since.
By the way, I didn’t disconnect batteries when I did it.
Michael

 

[Tony6905]

Hi All,

I have C180 Kompressor (three door version).
Have a problem with RF remote control.
The IR is working. BUT! I daily use my car.
The IR is working fine in closer position (I know this is another problem) open and close the car with one click on remote key every day. When my car is stay on weekend in the parking space, the IR just very hard opening the car on Monday morning. Need pressing the open key on remote, 2-3 times.

The car main battery is good. The voltage is over 12Volt. (the enginee off)

I checked the 7.5Amp fuse in back side in package area.
The fuse is ok, the RF amplifier is working. When I removed the fuse the radio sound is off.
I checked two small coaxial connector output on RF amplifier.
Both fine.

I think have the second battery (the auxialary battery) in the car and the problem source is that. The battery is end of life.

Where find the second battery? I removed the plastic cover in package area, but not found. I searched on passanger side.

I tried my both remote key.

Thank you any Idea.

 

[samble]

Thanks Michelten,

Will disconnect both my batteries and give this a shot

I take it you have never had any issues with your locking ever since?

Your symptoms sounded very much like mine, only being able to lock/unlock car via IR sensor on the door handle.

Hi there I am a new here and I know that the post is 2 years old.
I have exactly the same car 03SL55AMG and have just developed the same problem. The IR would appear to work, but only on drivers door, with lock and unlock but not the RF.

The PSE had blow and I have replaced that and now all locking and unlocking works, including the soft close on boot, but not the RF.

Did you every solve this?

Thanks
Si

 

[BlackC55]

Have you tried your spare key?

 

[samble]

Both keys are the same, changed batteries no difference

 

[BlackC55]

I expect the antenna maybe at fault. Need to plug it in firstly to a Star and go from there. I have a RF and IR tester at work to test keys, that might be an idea just to double check them.

 

[samble]

I don't think it is the keys as both were the same, I know there is a fault on the IR on the passenger side and people say that it is a dry solder issue, which I will try and sort.

Was just wondering if there was a fuse or something that might have blown when the PSE went, that did blow the PSE fuse, but when I fixed the PSE I replaced the fuse

I guess the answer is the Star and see if there is any fault code!! :-(

thanks for your help

 

[BlackC55]

They don't often leave codes when they fail. Did you code the PSE pump when you replaced it?

 

[samble]

the problem was simply the pump, which I replaced, not the whole unit so I didn't need to do the coding

 

[samble]

If anyone comes here my solution was the RF receiver on right. pn A2308201189

 

[MT01]

Hi, this is great news as it’s the first thread that I’ve read with this solution - can I ask if you were able to check the RF Receiver or plug in a new one without removing the dash ( I understand this is needed to replace the receiver) - how did you diagnose this? Any guidance would be appreciated- thanks

 

[samble]

Hi, this is great news as it’s the first thread that I’ve read with this solution - can I ask if you were able to check the RF Receiver or plug in a new one without removing the dash ( I understand this is needed to replace the receiver) - how did you diagnose this? Any guidance would be appreciated- thanks

Yes I felt the same frustration that people offer advice but no thread with the solutions.

The first place, small Indy, I took it to had not see this problem on an SL but had seen it on a C class and the solution was the receiver. They were busy having be closed with the the lock down and couldn’t do much more and nothing showed on the Star.

They mentioned that the dash might need to be removed to get to the part, WIS says you do

I took it to another Indy and they checked all the connectors, wiring loops and came to the same conclusion that we should change the receiver rather than spend hours more.

The part was on back order with Mercedes in Germany and cost £246 excl Vat. They also said it could take months to be made.

I found people selling used ones on EBay and bought one from Germany and one from Lithuania. The German one took 3 days to come and about an hour to fit, you can access it without removing the dash from the right foot well. A very happy me.

the Indy is in west London who did it and can let you have his details if you like

I am still waiting for the other one to arrive, not sure what I will do with it when it does

Hope this helps

 

[MT01]

I might just have a go myself so many thanks for the feedback- I did previously take a look from under the dash to check it had power to the receiver but made no attempt to remove it. If I struggle I may need those details. Thanks again and fingers crossed

 

[samble]

Good luck

At first they didn't think mine had power which sent them on a wild goose chase, checking all the cables etc. There were some benefits because they fix the broken airlines under the seat while the were checking the cables!!

It would appear that the receives was shorting out as when disconnected the power was fine, but dropped when connected.

 

[MT01]

Just a short update - following your guidance I was able to replace the receiver, it wasn’t that difficult but unfortunately it didn’t resolve my issue. I was able to check the signal wire ( once removed) whilst pressing the key remote and it reacted immediately, confirming RF signal received but unfortunately confirming the fault is elsewhere ( OCP, EIS, SAM etc? ) back to the drawing board . Thanks for the advice again.

 

[G7Wagen]

They don't often leave codes when they fail. Did you code the PSE pump when you replaced it?

Can I ask.. if you fit a new PSE pump into your R230 without coding the pump to the car what effect will this have?
Thanks

John