PSE problems with my 1998 R170 SLK

[cmotandy]

Hi All,
I've got some problems with my SLK. My Alarm siren died, none of my keys now remotely lock/unlock the car, I've got a Start Error and the hazard warning lights flash when I try to start it. Is the car in some sort of theft protection mode? The central locking works from inside the car using the dash button. I had the PSE off the car today - looks fine inside. However, the white connector has a bit of corrosion (green coloured) and one of the pins looks a bit dodgy. The PSE is making a ticking noise - video posted here http://www.youtube.com/watch?v=4TzWg...ature=youtu.be. It goes off when the black connector is disconnected. This is the power source I presume? I'm assuming the start error is because the keys aren't synced to the car (and the re-sync process didn't work) and the alarm is on as the indicators flash when I try to start it although the siren ceased last month. Is the PSE beyond salvage? Any R170 experts out there who can help?

Thanks

Andy

 

[Dec]

That sounds like a relay clicking at double speed, when the alarm is triggered the indicators should flash at double speed.
As I understand the alarm siren is the “brains” of the alarm, your alarm has been triggered because of an internal defect within the alarm siren so it won’t allow you to start the car.

Best bet is to replace the siren from MB dealer… around £100, very common for the siren to fail, I replaced my own last month.
Just my opinion, others may have a different take on the fault.

Dec

 

[Ted]

You don't need the pse connected for the car to run, so you can eliminate that.

 

[cmotandy]

So, if the alarm is activated, but not sounding as the siren is goosed, would that cause my Start Error? Is it in some sort of theft protection mode? And is the alarm sounding because the siren is defective? Does the alarm also control whether my keys remotely operate the Central Locking? I want to get into the alarm siren to have a look, just need to wait for it to stop raining. One of these days...

Any help appreciated.

 

[Dec]

When you unlock the car with the remote, you also disable the alarm, does the locking /unlock with the remote work as it should?
When does the alarm(hazards) go off, when you unlock or when you try to start the car?

I have an alarm that is in working order.
If I were to unlock my boot or door with the metal key blade, the alarm would be triggered, the siren would sound and the hazard lights would flash at double speed, all that is normal, if I then either unlock the car with the remote fob or put the remote into the ignition and turn the ignition on then the alarm would stop.

In your case, you have a defective siren, that siren could be triggering false alarms and it could be stoping the remote from disabling the alarm, it shouldn’t stop the remote from disabling the alarm… but the siren is defective so no way of knowing for sure.

There should be back up batteries inside the siren, these are probably knackered, perhaps leaking and possibly destroying the circuit board.
I changed my siren recently, it was the original and about 14 years old, the rechargeable batteries looked ok in that the weren’t leaking, however the siren circuit board was rotten. In my case, the alarm system worked normally but the siren didn’t sound when I intentionally triggered the alarm.

Defective sirens are well known for triggering false alarms.

To open mine, I had to cut it in halve with a hacksaw.

Dec
Edit, condition of my siren PCB

http://www.scriblink.com/bg_images/708-siren pcb.jpg

 

[cmotandy]

The Hazards go off when I try to start the car. The remote lock/unlock doesn't work with any of the 2 keys I have. I'll have a go at it tonight as the sun is shining for once!

 

[Dec]

Check that the battries in the remotes are good and test the remotes in a digital camera, do you know how to do that?

Dec

Edit, your remote is different to below key but same idea, see below.
Have you checked all fuses?
Also, unplug the siren, see if that makes any diffrence.

http://www.youtube.com/watch?v=Q4iU1t_unbw&feature=related

 

[Sparky1]

Thanks, very good information.