Peugeot Forums banner

1 - 13 of 13 Posts

24 Posts
Discussion Starter #1
My wifes 407 started to play up today.
Its an 2004 407 saloon 2,2l 24V petrol

Reading of fault codes I get:
From the BSI F99C (Petrol pump actuator Circuit"
from the Engine Control (MM6LP)
I get 13 codes:
P0105 Most likely the MAP sensor, changed it today.
P0445 Evaporative Emission System Purge Control Valve Circuit Shorted
P0261 Injector 1 – circuit low
P0264 Injector 2 – circuit low
P0267 Injector 3 – circuit low
P0270 Injector 4 – circuit low
P0076 Intake Valve Control Solenoid Circuit Low Bank 1
P0135 O2 Sensor Heater Circuit Bank 1 Sensor 1
P0141 O2 Sensor Heater Circuit Bank 1 Sensor 2
P0351 Ignition coil A, primary/secondary – circuit malfunction
P0353 Ignition coil C, primary/secondary – circuit malfunction
P0354 Ignition coil D, primary/secondary – circuit malfunction
P0352 Ignition coil B, primary/secondary – circuit malfunction

Som of the other boxes reports U1208 and U1108, most likely CAN-bus Errors.

So, anyone that have an Idea what the heck is going on?

1,024 Posts
Hmm, well...

How are the battery and the alternator?

Are they described as permenant or intermittent?
Will any of them not clear?
When you have cleared them which come back first?

24 Posts
Discussion Starter #4
They did clear, then I started the Engine, left it on idle for half an hour, then it suddenly stopped with the fuel pump error.
That error did not clear, however the Engine started after a while.
Mind you it is quite hot today, might be the cause ( not the cause actually, but speeding up the true cause a bit)

Will investigate more tomorrow.
Also found a couple of threads with a similar issue, seeems to be the fusebox (BSI) relay that was the cause. Not necesseraly the same cause for me though.

14,956 Posts
I think you may well find it is the same cause i have seen the same thing on a few 407s they seem to be more prone to it for some reason.

Its not the BSI though its the BSM different thing entirely thats why i say under bonnet fusebox.

24 Posts
Discussion Starter #9
Today, the car died after som 15 minutes, connected Diagbox, diagbox said that the Engine ECU was unknown type, 10 minutes lateer the car started, no diagnostic codes present, except CAN bus errors

24 Posts
Discussion Starter #10
So, obvious the fault is in the BSM, since it appears that relay 2 is not pulling.

Ordered an "New" bsm from a scrapyard, unfortunatly, it has the same behaviour or fault.
So I decided to take the BSM appart.
I managed to carefully take the back off, with a saw.
Now, obviously it would not be that simple, since there is a piggy-back PCB on the relay/fuse pcb.
That PCB needs to be removed.
There is some 89 solderpoints that needs to be unsoldered, a proper de-soldering station is absolutly necessary , do not try it without it.

Personally i use a Weller desoldering station with built in vaccum pump.
Similar to an WRS1001 ( cannot attach more images, sorry, you have to google it)
Still one have to be very carefull in order to avoid damage on the PCB.

Removing the relay, the you need at least a 200W soldering pen, Start with applying solder flux (proper one for Electronics), then resolder with new solder, to increase the wetting, the I use a desoldering pump, and some desoldering braid. (and a lot of proper flux), desolder with care.

Now I removed the relay, dont think it actually was necessary, unfortunatly it was a destructive removal, thanks to the Silicon filler.
The relay looked quit okay on the Contacts, however, the coil could still be affected.

I am planning to replace it with a standard car-relay, as an middle Control relay and put two fused relays for the actual load.

There is obviously quite a lot of load on this relay, Petrol pump, Injectors, ignition, heaters for the oxygen sensors, and various other heaters, such as crank case ventilation heater etc.

If the repair succeds, I will repair the other faulty BSM, so I have one as spare

Here some images:
First Image: The CPU-card that needs to be removed.
Second Image: The relay/fuse pcb
Third Image: The culprit, heat afffected soldering joint
Forth image: Relay removed.
Fifth image: Relay removed


21 Posts
Would it be possible to find a 12V feed from the Ign Switch and use this to power a Relay that then feeds 12V into that fuse that feeds all those circuits?

24 Posts
Discussion Starter #12 (Edited)
No, it wouldn work, because there are som "tests" carried out when ignition is turned on.

Basically, the ECU actuates the pump for a few seconds, end then shuts it down.
If not, error code is issued..

But now I finally managed to get it working.
"Repairing" the BSM-Box was a total failure.
However I managed to find a way to do it externally, without opening up the BSM-box.
This is how it is supposed to work.

When Ignition is turned on, Relay R1 is actuated, This relay feeds the coil for the broken Relay R2
It also feeds 12V to Connection Black #5.
After a few seconds Black#8 is taken High (+12V) (this is the Control signal for relay R2), Relay R2 feeds the fuel pump, injectors, and ignition coils.
When this signal is taken high, relay R2 is opening, and there is no feed to Pumps, injectors coils etc.
When starting/running this signal goes low, actuating relay R2, feeding fuel-pump, injectors etc.

So the solution is as follows.
Two external standard 30/40A car relays.
A relaydriver created with one N-channel Power MOS-FET transistor i.e IRF520.
One diode 1N4002 or similar.
One bipolar NPN-transistor, i.e. BC547.
Two 6,8K resistors, one 1,8K resistor.
Some stripboard, veroboard or similar.
(I will do a complete schematic, and post it as well).

Terminal 30 on the relays should be connected to battery+ with one 15Amp fuse to one of the relays and a 30Amp fuse to the other.

Terminal 87 on the relays is connected as follows:
15 Amp fused relay to the wire that is connected to the grey connector, terminal #5, do not cut the wire.
30 Amp fused relay to the wire that is connected to the black connector, terminal #4 or #2 (choose the fatest wire), do not cut the wire.

The relay coils, terminals 85, should be connected to wire 5 on the black connector. Cut som inslulation from it and solder in a wire, insulate it.

Relay coils terminal 86 goes to the driver board.

The actuating signal is soldered in to the wire on the black connector, terminal 8, cut some insulation and solder it in.

This will full replace the function of R2 in the BSM, and all motor-codes should go away.

Leave the original fuses in, so the BSM is "Back-fed" from the external relays, thus enabling "hidden functions" in the BSM.

If the car has an Air-pump, a third relay is adviced feeding the wire connected to the gray connector, terminal#1 use a 30Amp fuse for this relay.

Now I have som CAN-Bus errors, but that will be Another thread.
1 - 13 of 13 Posts