Technical Random mystery motor Central Locking problem.. :D

[Ralf S.]

Not Fiat, or 500..... but I'm not getting any joy on the Renault forums and they're not usually as precise anyway... so apologies to try here.. I'm just looking for any guidance that can help me fix a problem.

The short version of a long story is that I'm trying to activate the C/Locking via the IR key on a 99T Megane coupe. Locking/Unlocking the car via the key button is the only way to disarm the immobiliser after the battery has been replaced (which it has, after standing for some time). This worked many times in the past .. and now doesn't. The car obviously won't start (immobiliser activated) - everything else is good.

My problem is that the C/Locking using the key does not now work all of a sudden.

I've tried the main key which was fine before the new battery (little red light works) and also the spare key (which needed a new battery but now the little red light works).. but the system is non-responsive.

If I'm inside the car and lock the C/Locking using the "lock" button, the C/L will work.. so the C/L itself is fine.

So either the keys have become mis-matched from the "receiver" and it no longer recognises the keys.. OR the car is getting the key signal but can't trip the C/L (which otherwise works). I have no idea where the IR receiver is (someone Renort suggested it's on the BCM).. so I can't begin to work out where to look for issues.

The car had a leak (sunroof drain blocked) so I suspected some water damage.. but I've had the headlining and the whole lower dash apart and there's no hint that the electrics got wet.. all nice, dry and dusty.... so I don't know what went wrong, or why.. nor how to sort it..


Ralf S.

 

[bugsymike]

I have had customers in the past with Renault locking issues, one several years ago with a Laguna that used a sort of credit card type key spent £400 pounds with the dealer to fix it, it then stayed in a tyre fitters for two days as it had locked it's self again. Whilst handing me the key card to do an MOT it locked it's self and as we looked at the key laying flat in my hand it then security / double locked! He sold the car and only bought new other makes!
I am in Torbay and use a Auto Locksmith for any issues such as reprogramming keys etc. It may be worth asking him if he can recommend some one near to you, his details are www.carkeystorbay.co.uk and 01803 320870. No guarantees obviously, but he did good for me.

 

[porta]

Right, bear with me whilst I type and think back…I believe that the remote system is not unlike Fiats from the era. I seem to remember that, with the keys, you should also have got a ‘key card’ with a number on it…now this is where it gets hazy…I can’t remember how to put the code in but seem to remember that the sensor is up with the interior light binnacle, (it’s also an issue for water ingress), and there is a ‘reset button’ on the module to put the code in.

 

[porta]

Just found this and I think I was almost right…

https://www.honestjohn.co.uk/forum/post/index.htm?f=4&t=70723

Seems it’s not uncommon!

 

[Ralf S.]

Yes.. the Renault immobilisers seem to be a proper PITA, not least because they fitted several different systems.

This (my sister's) car doesn't have the credit card key doodah.. it's a regular key with a single button. I've tried various of the key fob voodoo hacks on Youtube but I can't find precisely this problem, so unsurprisingly, no luck.

Right, bear with me whilst I type and think back…I believe that the remote system is not unlike Fiats from the era. I seem to remember that, with the keys, you should also have got a ‘key card’ with a number on it…now this is where it gets hazy…I can’t remember how to put the code in but seem to remember that the sensor is up with the interior light binnacle, (it’s also an issue for water ingress), and there is a ‘reset button’ on the module to put the code in.

Good call... apologies that I wrote "IR key" in my original post. I was thinking of "RF". The IR system does have a sensor in the roof.. but this car has "radio" and the sensor is (one poster suggested) on the BCM. I've nevertheless dismantled the overhead light unit to check what's in there.. it's just the sunroof motor... ( I was hoping to find a sensor and some water ingress/damage might be visible) but a) there's no sensor and b) it's bone dry in there.

Ironically in the past the car's battery has drained and the immobiliser code didn't recognise the key, although the central locking always worked. This time the C/L has gone moody... (I presume that the immobiliser will release, if I can get the C/L to lock-unlock via the key).


Ralf S.

 

[porta]

Yes.. the Renault immobilisers seem to be a proper PITA, not least because they fitted several different systems.

This (my sister's) car doesn't have the credit card key doodah.. it's a regular key with a single button. I've tried various of the key fob voodoo hacks on Youtube but I can't find precisely this problem, so unsurprisingly, no luck.



Good call... apologies that I wrote "IR key" in my original post. I was thinking of "RF". The IR system does have a sensor in the roof.. but this car has "radio" and the sensor is (one poster suggested) on the BCM. I've nevertheless dismantled the overhead light unit to check what's in there.. it's just the sunroof motor... ( I was hoping to find a sensor and some water ingress/damage might be visible) but a) there's no sensor and b) it's bone dry in there.


Ralf S.

You’re right about the confusing number of systems Renault had. Some you can identify, but not always, such Phillips, some you cannot, like the ones that are just stamped ‘made in France/USA/Italy’.
Wehn I said key card, I didn’t mean the one you slot in, just the one, with a number code. If there’s no sensor up there it will be the type under dash or next to ecu or door looking module, I think

 

[porta]

I thought the BCM was post 2000?
I’m trying to remember which cars it was that you could reprogramme the keys by putting it in limp mode:
Key in ignition
Hold down accelerator peddle
Switch to ignition on
Pump accelerator thre times slowly
Start engine…if it starts…
Hold down door unlock on keyfob

 

[Ralf S.]

The car's handbook says the RF key "may need to be re-synched if you change the battery", by pressing the button for 10 seconds/till the LED light goes out, then double-pressing the button.. so I was hopeful that would do it, but I tried that with both keys and again, no luck. I'll try it again tomorrow but I'm proper perplexed.

The fuses look okay and there's no reason why anything should have just stopped working ... the car was parked up working fine... the battery was taken out, charged up and replaced... and now the remote C/L is offline


Ralf S.