406 Key Symbol - BSI Fault

[xsaras4ever]

Hello ,
our 406 (hdi estate) was unused from February and was left with the battery disconnected.

When we tried to use it recently, the key symbol was lit.

Re-coded the keys , but symbol still lit.

Shows BSI Fault on PP2000 -

"Permanent fault - connection between built-in system interface and engine management control unit"

Will check connections on ECU and relay and report back , but any help and advice would be greatly appreciated.

[jimmymarsbar]

Check the earths and interconnections for corrosion due to water, and especially check the engine management ECU. If it's been sat for a while, there could have been a bit of water build up. Green fluffy deposits on the terminals are signs of corrosion, as is white fluffy deposits on the ECU casing.

[wheeler]

does PP communicate with the injection ECU ?

[xsaras4ever]

Hello to all , checked and cleaned all fuses today - including those in engine bay.

Checked and cleaned all terminals on ecu.

Still key symbol lit.

Will put car on a trailer and bring it home so that we can have a better look at it and put it on PP2000.

Thanks to all for the help.

[Oldpug]

My mate has a similar problem,key symbol showing,non start,various things not working.
He was advised to lift up the carpet in the driver's foot well???? he did and lo and behold the big wiring loom and a few multiplugs were in 2 inches of water.Apparently this is a know problem with old 406`s so have a look under yours.
How did you reprogram your key? he has been told it must be done via a Peugeot diag` tool.

[spider]

You can generally tell if its got this if you carefully brake hard and if its 'bad' you'll hear the water running back / forwards in the sills ( ! )

I've only seen one or two that had this 'issue' though.

Its more likely I think given the floor construction possibly the vehicle may of been caught in a flood. I do wonder what really happens to these cars and if they are really 'dried out' properly, somehow I doubt it.

The 'key' light is quite rare to see on a 406 as unlike the Xantia for instance the symbol very rarely actually lights up. I think the later 306 is the same (phase 3 2000 models) these have a key light if memory serves but its not 'connected' at the other end of the loom.

[xsaras4ever]

Hello to all , back again on the 406.

No , not been flooded, no water in carpets.
We re-coded the keys with PP2000.

No chattingi to injection ECU , no matter what we do - even on our crappy Lexia/PP2000. Key symbol still lit - all fuses good - all connections good - no sign of fluff or corrosion HELP.

Saw on another posting somewhere to check for 12v on wiring to ECU on one particular terminal and if absent cross with another 12v supply - but cannot find the posting now.....

[xsaras4ever]

Hello again,
some progress.

We have disconnected the large relay beside the ECU. It has 15 pins.

With ignition off, we have 12v at pins 3,8,11 and 15.

We bridged with copper wire from pin 8(12v) to pins 1,2 and 9.

Now when we turn on ignition we do not get key symbol, neither do we get "ignition fault" on dashboard.

Also, our glowplug light comes on and then goes out.

However, the in-tank pump does not run and the car does not yet start - but it is a feeling of progress.

Any comments most welcome.

[Peter.N.]

I had this with my original 406 and it was because the car had not been used for a while and the whole interior was soaking wet with condensation, on a nice bright day I left all the doors open and it dried out quite nicely and started, I then made the fatal error of leaving it standing again, next time it wouldn't start, I removed the BSI unit from under the dashboard and found water had been leaking in through the bonnet pull cable grommet, although I couldn't find any sign of it inside sadly it never started again and is now my spare parts department.

If you can borrow a good BSI and ECU from somewhere you could try swapping them over.

Peter

[xsaras4ever]

Hello Peter.

Thanks for the posting but do not think it is water. We have had very little rain here this year, the car was bone-dry.

We think that pin 4 on the relay is for the pump , can anyone confirm ?

In fact, does anyone know what each of the 15 pins are for ?.

We are next going to check if any of the pins go from zero to 12v when the ignition is switched on - to determine
if it is the relay or the ignition feed to it which has a problem.

Thanks in Advance

[Peter.N.]

Will be very interested to know if you fix it, and how.

Peter

[xsaras4ever]

Hello again,

so with ignition off , pins 3,8,11 and 15 have 12v and pin 7 has .36v .

But ---- its exactly the same with ignition on.

So maybe the relay is ok , it is just not being activated - looks like back to BSI or fuses etc.

It would be great to know what pin is supposed to have 12v with ignition on, because then we could patch 12v to the relay and get it to start.

Wiring is not our strong point - any experts out there ?

[xsaras4ever]

just bridged to pin 4 - pump activated - car started and running.

it must be a feed to the relay ?????

[wheeler]

Pins 3, 8, 11 & 15 should be battery live.
Pins 4 & 5 are joined internally & are outputs to the secondary side of the relay. 4 goes to the fuel pump & 5 goes to various auctuators & glow plug relay.
Pin 10 should be earthed by the injection ECU, when pin 10 is earthed by the ECU it activates the first side of the relay. this then outputs to pins 1, 2 & 9 which are joined internally. Pins 1 & 2 supply the injection ECU with 12v & pin 9 supplies the fuel pressure solenoid.
When pins 1,2 & 9 go live this also powers up the secondary side of the relay.
The secondary side of the relay is earthed by the ECU on pin 7 of the relay.
Its much easier to understand when you are looking at the diagram.

[xsaras4ever]

Big thank you Wheeler, we think we understand.

We have no pin 5 , but thats apparently normal in some cases.

With none of the pins coming up to 12v at ignition , how is the relay activated - like you say - by earthing to the injection ECU ?

To test the relay, if we re-connect the relay and force-earth pin 7 and 10, should it activate ?