w202 whole lot of electric problems

Page may contain affiliate links. Please see terms for details.

chrishull

Active Member
Joined
Dec 22, 2016
Messages
88
Car
c240 w202
hi everyone

i went out to my car yesterday and my central locking would not operate, i used the key blade to get into the car and started the car no problems. now my wiper stalk doesnt work at all, no wipers or indicators, the anti theft switch is flashing and the rear demist doesnt work.

Any ideas what this could be? could it just be the battery in my remote running low? i tried my spare and that was the same.

Thanks
 
Cars these days are very picky about good voltage. A plan of action would be to clean the battery connections as well as the earth (grounding) connections. Cleaning means disconnecting, freshening the surfaces and reconnecting.
Measuring the output voltage of the alternator is also a useful task. Should be about 14v.
How old is the battery?


Sent from my iPad using Tapatalk
 
i have tried getting in the boot but the key doesnt work and the electric release doesnt work :( the battery was replaces around 2 years ago, everything else works, power folding mirrors, headlights etc. car drives its just if it rains i wont be able to see where im going or i cant let anyone know which junction i want to come off a round about.
 
i was hoping it wouldnt be that. was it expensive?
 
i managed to get in the boot and one of the 5A fuses had blown from the central locking, i replaced it but still no joy, does the key need to recoded to the car again?
 
i managed to get in the boot and one of the 5A fuses had blown from the central locking, i replaced it but still no joy, does the key need to recoded to the car again?

You should check if the fuse is blown again. When the fuse kept blowing in my W202 a few years again it turned out to be the central vacuum pump.
 
the fuse is ok now, there are around 7 altogether front and back related to central locking, i would of thought if it was the eis then the central locking would work at least? the car starts and drives fine, the hazards work just the above faults
 
Don't suppose you can suggest where I should check first?
 
As long as the key is starting the car, then that function is fine. Do you have a multimeter or even a simple 12 volt light up tester to check out the wiring to the fuse boxes / SAM units. I do not have a wiring diagram for your car, having one is handy,Google may help. Remember that just because a fuse is O.K. it does not mean that the power is getting to the fuse and out the other side. Often fuse boxes and SAM units suffer from water ingress, especially on older vehicles, and it is not until you remove them you can see the damage. So you have no wipers, no indicators and no central locking, you need to identify the common denominator in all these, using your wiring diagram. If all these items require power from the front fuse box / SAM unit the begin there.
Had it been icy before the wipers packed in? ( Has been icy here in Fife. ) So many folks defrost the screen and do not free off the wiper blades, which remain frozen to the screen and this can cause an overload on the wiper motor. If you are lucky this just blows the fuse, and if not, then can stuff up the motor. Water ingress can freeze and cause many problems, just drying out fuse boxes and SAM units can help, but ultimately replacement is the only cure unless you are handy with a soldering iron.
Best of luck.

Steve.
 
Grober , you are like a walking encyclopaedia! Happy New Year
 
can anyone advise how to pair my key to the car, i have changed the batteries this morning and thinking could this be the problem? or a faulty rcl module?
 
Last edited:
can anyone advise where to check first from what grober has posted? i just cant understand whats happened, the night before it worked.
 
It looks as if you have a problem with the RCL [remote control locking] system. Your key transponder is recognised by the DAS system OK when placed in the ignition hence you can start the car.
First thing to try is whether the key remote is putting out an IR signal - you can check this with a digital camera which will detect IR as a white light on screen.
To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.
 
Last edited:
Yes I've just tried this again with both keys and they both have white lights on.
 
Could someone tell me where to find the central locking module? Is it in the drivers door? I will start by ordering a replacement

Sent from my Moto E (4) Plus using Tapatalk
 
GF80.30-P-0002A

I would seriously council against replacing units willy nilly. As you can see the system is complex with communication between units via the cars "network" i.e CANBUS. Best to get it on a good diagnostic system to get any fault codes read out-- to get a better idea where the fault lies. With older cars these problems often arise from water ingress shorting or corroding electrical contacts. If there is evidence of this when the fault is located then it has to be investigated otherwise any replacement will tend to suffer the same fate.
 

Users who are viewing this thread

Back
Top Bottom