Key Fob / Immobiliser Problem

[scotty_d]

robsco said:

I wonder whether they lose the code when the car is sat unlocked for a while? Virtually every time I have left the windows down and car unlocked, in any of the TVRs, it has caused problems later on with door opening/locking/windows etc.

My car has been left like that since I got it and I work away for weeks at a time with no issues, just the immobiliser starting to pack in.

[esso]

I'm a little confused now between what the immobilizer and the alarm actually do.Does the immobilizer prevent the car being started? because I cannot disarm the alarm but I can start the car,so is it an alarm issue or an immoboliser issue?

[scotty_d]

esso said:

I'm a little confused now between what the immobilizer and the alarm actually do.Does the immobilizer prevent the car being started? because I cannot disarm the alarm but I can start the car,so is it an alarm issue or an immoboliser issue?

The immobiliser disables the fuel pump and starter motor circuit (little more to it but don't want to post to much on the open page) , they are tied in with the alarm box that is the receiver for the key fobs as well, it does sound like your m36t is playing up, I would give Dave a call he will be able to tell you in minutes what is going on, he knows these systems like the back of his hand.

[esso]

[quote=scotty_d]

The immobiliser disables the fuel pump and starter motor circuit (little more to it but don't want to post to much on the open page) , they are tied in with the alarm box that is the receiver for the key fobs as well, it does sound like your m36t is playing up, I would give Dave a call he will be able to tell you in minutes what is going on, he knows these systems like the back of his hand.[/quote
OK,thanks for your help Scotty,I will give Dave a call. ;-)

[esso]

Well I seem to have sorted my little issue,disconnected the battery, put some new key fob batteries in and after a bit of tinkering the alarm has reset itself and it seems to be working fine!

[robsco]

Good news I nipped over to mine and disconnected the battery tonight, will go over later in the week and see if that has resolved it.

[Cawley101]

Gazzab said:

PM

Sorry to open an old one but ive the same problem anyone help ?

[Cawley101]

milothepeanut said:

Thanks for the reply.

I have tried the battery off and tried the key of doom but it's neither of these.
The wierd thing is that the led on the slot for the touchkey receptacle wont stop flashing.
I really need to move the car so if anyone knows how to by pass the immodiliser could they
pm me.
Here is a picture of my doggy looking sad because Daddy can't start his car.

Same issue

[mac315p]

Cawley101 said:

Same issue

If you are in the car and you have the 'no response from either fob but immobiliser light on' problem and you've disconnected the battery (for at least an hour or so - last time I had this issue I left it overnight and it was sorted) then you'll need to ring HF Solutions most likely ('Google' them). Also worth checking the state of the car's battery this time of year.

If you aren't in the car then if you post whether you have an early or late car someone will hopefully PM you and let you know how to get in - although with a post count as low as 2 there may be some reluctance to do this. . .

[Cawley101]

its an 2001 evo 7, the fob will unlock and lock, but the park lights remain on (i dont understand) and it trys to start but wont fire
ino what your saying about post count but ive Googled and this has been the only thing that ive came across the same which lead me to the page .

[Juddder]

Cawley101 said:

but the park lights remain on (i dont understand) and it trys to start but wont fire

Check the fuel pump is priming - you should be able to find where it is on your car from the web / forums and then get someone to listen when you disable the alarm for it sounding

On a Cerbera you can hear it whirring from the drivers seat when you disable the alarm as the fuel pressure is high and it's just behind your left shoulder in the rear passenger wheel arch

If the immobiliser is disabling the fuel pump (mine has a switch added to do this) then the car will turn over but not start

I would imagine you can then test with a temporary +12v feed to the fuel pump

[Alanjustice0869]

I have a b class Mercedes, and 2 weeks ago I was driving and stopped at a shop ,when I got back into the car and put the car fob in and turned it all I got was one click and car wouldn't start ,it then started about 30 minutes later ,this has happened now twice in 3 weeks ,any information would be grateful accepted.

[Juddder]

Alanjustice0869 said:

I have a b class Mercedes, and 2 weeks ago I was driving and stopped at a shop ,when I got back into the car and put the car fob in and turned it all I got was one click and car wouldn't start ,it then started about 30 minutes later ,this has happened now twice in 3 weeks ,any information would be grateful accepted.

Not quite the right forum for a question about Mercedes (it's about Cerberas), but funnily enough I have an M-Class also that did similar

It was the crank position sensor playing up. When the car was hot it failed, so the car wouldn't start - when the car cooled down it worked correctly so the car would start.

Take it to a garage with the Mercedes diagnostics software (independents have this too) and get them to check the error codes