Peugeot 306 XS - Red and Green Light - Car won’t start

Hi, I’m hoping someone will be able to help me, i’ll explain what the
problem is but forgive me as the history of this is quite long.

I have a problem with the immobiliser on my Peugeot 306, when i turn
the ignition on, both the Red and Green light comes on on the keypad
and won’t accept my 4 digit code, had a mechanic look at it and he
said the ECU had locked out, so found a place that sorts out ECU’s and
they said make sure it not an earth fault before sending them the ECU,
so the mechanic checked and said no, there’s no earth fault!

So sent ECU to be done, came back, still the same problem, ECU place
said it wasn’t ECU, so decided theres nothing else i can do but to
take it to the Peugeot garage, they had a look, connected it to their
computer and said they couldn’t find what it was, can only be the ECU
locked out, so i sent the ECU back to the ECU repair place and they
said it wasn’t the ECU and to tell your garage its ’PIN 18 - Battery
supply fault’, so i did, they said they’ve completely checked
everything and cannot find the fault and they still believed it was
the ECU, which left me well in the s**t, a private mechanic, the
agents and an ECU repair place, all these so-called experts still
haven’t found what the problem is!!

Anyway, on verge of scrapping the car, i managed to get hold of a
second hand ECU, keypad and code to try, which show’s up with the
exact same problem which leads me to believe its not the ECU.

If there’s anyone out there that can offer me any advice or info on
what to do next i would be very grateful, i’m assuming it must be an
earthing problem but haven’t got a clue how to find it, cleaned up all
the earthing points i can find but still no joy!

I’m about to string myself up as the car has now been out of action
for over a year, so any help would be great!!

 

Just as an elimination have you tried pushing the button on the fuel
cut-off switch? Assuming of course you have one. You haven't mentioned
the year of your car, but the very early ones didn't have them fitted.
I think it was around '95 or '96 they started fitting them. I know
when they are operated they give the same problem with the lights.
Come to think of it, the fact you have a keypad means you almost
certainly have a cut-off. I think it's on the N/S strut turret to the
rear of the battery, a square device with a rubber top. If it has been
activated you will hear a small click.

 

Thanks Nigel, Its a 96 and does have a cut off switch, which i have
tried but wasn’t a 100% sure if it was activated or not! When pressed
it does click so does that mean its activated? if it is, how to i
unactivate it??

Keep the suggestions coming please folks, any ideas very welcome

 

If it clicks when pushed it is then not activated. So it should then
NOT cut off the fuel or affect the keypad lights. BUT it should only
require pushing once. It should only activate when in an accident. Or
if it is hit hard on the side of the unit. I haven't come across these
units going wrong, but never say never!! You could try taking the
cut-off out of the equation altogether by taking the connector off and
pushing some thing up inside the plug to short the wires together.

 

Hi. I've had what seems exactly the same problem with my 406.Anyway the
auto-electrician has towed it away and tells me it's going to cost between
£350-£450 to fix.(just to make the thing run again)It's apparently a
solenoid that controls the fuel pump needs bypassing,so afterwards it wont
have an immobiliser.
Most of the money is for labour charges getting at this thing, which
peugeot have also made tamper-proof.
Anyhow...Good luck, if it is the same problem,I hope you can get it done
cheaper.