W210 alarm/immobiliser with infra red key

[sportyreptile]

Noticed this odd behaviour a few times, I unlock the car with the infra red remote, jump in and close the door the hazard warning lights flash, have to lock and unlock the car again with the remote before it'll start. The alarm doesn't sound just the hazards flash.

Would it be a failing door switch or something more complex with the immobiliser?

 

[Dieselman]

Either car or alarm siren battery on the way out.

 

[xdingo]

anyone can advise me please?
cant lock the car anymore, when I turn the ignition key it rotate but the green and red light flash simultaneausly, I changed the battery in the fob key, I disconnected the battery to reboot, still the same.at the moment look like the immobileser doesnt let me start the car.I would keep it like that and close lock the car from passenger door,it is just to isolate the immobileser,any idea?thanks

 

[sportyreptile]

Hi, did you disconnect the battery or at least half an hour? All day would be better.
Follow the key resync proceedure when you reconnect, the car should start. I had this happen to me in a London underground car park and this got me going.

I've had the car diagnosed on STAR and the two possible culprits are the interior mirror or the Infra Red Remore Control Unit that sits under the dash somewhere. Luckily since the all day battery disconnect the problem hasn't returned but at least I know what to go for if it does happen again.....I'd replace the mirror (£130 new ??? second hand) first then the IR ECU (£400 ish new, it needs to be coded to your car and engine ECU at the factory) if the mirror didn't cure the problem.

 

[xdingo]

thanks but I wanted to avoid this,this mean going to a mercedes dealer, which is not worth for the value of the car.thanks