FIXED! Megane 1, no rcl, no immobilser light, no start

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hayabusa1300r
Posts: 39
Joined: 04 May 2016, 08:39
x 2

FIXED! Megane 1, no rcl, no immobilser light, no start

Post by hayabusa1300r » 03 Oct 2019, 14:50

Hi,

Some background information. Bought the car (2003 Mk1 Megane Cabriolet 1.6 petrol ) earlier this year for fun as a 2nd car to take on road trips, low mileage, all the books, 2 x keys etc. Everything worked *fine* ( except the dash immobiliser light which didn't work which I attributed to the installation of a Cobra alarm which had its own immobiliser light on the steering wheel cowl). The battery though was getting lazy and had to jump start if not used every few days.

So bought a new battery, went to fit and I'd been given one that was slightly too large physically, so back to the auto factors (left Megane disconnected just walked there) got another came back and fitted, say 45minutes turnaround. Car turned over fast but not firing, cant get a spark, can hear fuel pump priming.

When I went to fit the new battery first off the remote central locking didn't open the car, the hazards didn't flash and I noticed the red Cobra immobiliser light on the steering cowl was not on, which I thought oh battery must be really flat. But with a new car battery the remote central locking off either fob doesn't work (does off dash button), and no red Cobra light (although I could get it to light and arm / sound the alarm if I locked myself in the car with dash switch). Both fobs red lights (RF one's I believe) work. So after scouring the internet checked ceiling light dome (even though a convertible and no aerial there) for water ingress, none. Checked internal fuses, on board and BCU, fine. Visually checked all under bonnet but cannot withdraw the big clear topped ones, they don't seem to pull out? Board looks all clean, as are block connectors underneath. Contacted a couple of local auto electricians and key people - each saying you needed the other or didn't have the necessary diagnostics.

Bought an elm unit, which can't communicate with OBD port. Bought a Clic (Chinese copy), couldn't communicate with car (OBD port). I found a very helpful guy on the net and bought a gadget that plugged into the port which switches the "system" from 1 to 2, as he said they can switch themselves after battery changes, mine had. He said he didn't think that what was causing the issues though, but the low cost meant it had to be worthwhile in my eyes. I did verify that the BCU was getting power as well.Tried switching 1-2-1 etc. no remote central locking, no start. Car turns over fine.

In frustration and wishing to eliminate as much as possible I have removed the Cobra, all the wires from it bar 1 were only spliced into the bcu, and the 1 that wasn't was easily reconnected as colour coded. Still no remote central locking, no start. I thought this would also reinstate the dash immobiliser light but it hasn't, I don't know if Cobra do some bridging in say the engine fuse-box though. All the lights, horn, roof, wipers etc. operate correctly. Just no remote central locking, no start.

Just today another locksmith to check keys hadn't lost code, he couldn't communicate with the car either. So after this long and tortuous epilogue, any ideas, BCU? I hate giving up, but don't know where to go with this.

I live mid-way between Derby and Matlock in Derbyshire. I have also posted on BBA reman site.

cheers

John
Last edited by hayabusa1300r on 09 Nov 2019, 09:26, edited 1 time in total.

hayabusa1300r
Posts: 39
Joined: 04 May 2016, 08:39
x 2

Re: Megane 1, no rcl, no immobilser light, no start

Post by hayabusa1300r » 08 Nov 2019, 14:43

Fixed, didn't know how to change the title - bought a silver 2002 Cabriolet with minor damage, swopped ECU, BCM and key fobs (ecu was a siemens but different numbers ). My blue cab started first turn and everything including roof appears fine. Fitted the blue cars ECU, BCM and key fobs and to the silver Renault and now had the same symptoms as the blue one had previously, no remote central locking, no immobiliser light, spins not starting. I swopped the bits to the silver Renault to "prove" it wasn't the loom in the blue Renault. Bonus is the silver was a 1 owner car, 57k miles, gearbox replaced by Renault due to very early failure, and apart from damage ( bonnet, slam and front cross member ) is in good condition, with a pair of new tyres, new battery and a CD stacker that mine doesn't have, so I will be stripping what I foresee as the useful parts for my blue one. Thank you for everyone's input, I believe my issues were the BCM.

User avatar
Paul-R
Posts: 3446
Joined: 07 May 2009, 16:24
x 236

Re: Megane 1, no rcl, no immobilser light, no start

Post by Paul-R » 08 Nov 2019, 16:09

Thank you for posting even though responses were, err, a bit thin on the ground.

Have fun swapping stuff over!

hayabusa1300r
Posts: 39
Joined: 04 May 2016, 08:39
x 2

Re: Megane 1, no rcl, no immobilser light, no start

Post by hayabusa1300r » 09 Nov 2019, 09:23

Lol sorry I copied and pasted, as I posted on BBA reman. I am over the moon it works, even though the ECU was slightly different physically and number wise. I have the "Roadbox" on my blue one, it really makes the car very useful ie camping, and I think these Meganes are well under rated, I plan on keeping this one as a 2nd car "forever" and enjoying lots of continental road trips!