cutting open Bosch pump in-situ on 306 to get to solonoid

[btsimonh]

ok, I've been trying to diagnose a sudden non-starting issue on my 306 non-turbo, 1997 (R). Ran lovely until this morning when it would not start.

Read everything there is to read on the net, got the circuit diags, tested, etc.
Tried a number of recommendations for immobiliser reset, to no avail. I don't have any extra buttons on the steering column, no keyhole under the bonnet, no keypad. Clicky key locks and unlock the car perfectly, have done battery disconnect, reconnect at key position 2 and 3, nothing has worked.

Certainly, I can't hear any solonoid action from the pump, although wire 8225 has +12, M128 is good gnd, oil level is (now) OK (it WAS a bit low). I don't know what should be on 820A... and I don't know what I have at the other end of 820A (goes to '82-' according to diagrams; may be near steering column?).

Diesel is present at the pump (not undone an injector).
Glow plugs have voltage, and are low resistance.

So unless anyone has any ideas, I'm assuming fuel cut-off solonoid failure...
Solonoid is within the Bosch pump, covered by 'Armour'. I found these images:
http://www.eastment.net/Boschpump2.htm
I've heard of people cutting into the pump in situ, and from the pictures, looks like I could go in through the top (cut the top out with a dremmel), after removing the fuel return hose, cut through the top of the control unit, and wire direct to the solonoid to test it. If it has failed, I should be able to make enough room to get a socket in...


If anyone has experience of this procedure, your comments and advice would be invaluable especially if there are other specific checks I should do first...

[davidireland]

Have done at least ten of them. The pump needs to come out. Remove the electronics and replace stop solenoid with a simple one wire on/off solenoid.

[chopper1192]

Careful you don't disturb the depleted uranium inside!

[btsimonh]

ok, cut the top off with a dremmel. It took 4 hours and some final hammering...

IT'S NOT THE SAME AS THE LINK I POSTED TO PHOTOS OF ANOTHER UNIT!!!!!

I have exposed the top of the potted electronics. Beneath the plastic, there is metal....

Does anyone have a 306 pump with the armour removed which you could post a photo of highlighting where the stop solonoid is? else I'll just have to start digging through pot.

P.S. I checked - no fuel from injector pipes when turning over. Checked the inductive coil around ignition switch, and it and it's circuit seem in good order. What is between this circuit and the pump (the electronics have 5v on them; the pump is all 12v, so I'm assuming there's another box somewhere....).

[btsimonh]

maybe I've been a bit hasty in my assessment. after a detailed look at the photos, it is the same. Next step is to cut into the immobiliser unit.

I could really do with a photo of the BACK of the immobiliser - If you have removed one of these in the past and have it to hand, PLEASE post a picture of the back of the unit to help me decide if/where to cut through it...!!

br,

simon

[teerak2uk]

its tight but i did one on a movano with the same setup as sometimes it would not read the key so the pump dont need to be removed and on the 3 wires just put the one that switches 12v with ignition on to the solonoid basically your 3 wires are but not in that order so check with a meter

1. earth
2. coded signal wire
3. 12v with ignition

[btsimonh]

ok, the job is complete & car running.

So, I cut off the top (4 hours with a dremmel, about 15 cutting discs).
The only part I removed from the car was the air duct .
The outer armour is about 1/4" thick.
This exposes the top of the immobiliser module. Cracked off the plastic outer coating, to reveal a soft metal casing. This is not as bad as it looks at first. I cut a slot towards the front of this, and the rear is unsupported, so you can 'peel back' the metal by 1/2" to reveal the potted circuit. The circuit has a 1/4" of hard potting compound, which breaks away easily, and the actual board is potted in a compound resembling gelatine. This can be picked away quite easily.
Revealing the board exposes a connection at the extreme top front corner, and applying 12V to this gave a satisfying click.
I then identified the switched 12v (my unit has 4 wires into it: +12v switched, gnd, oil pressure sensor wire, signal). the Signal wire shows 12v all the time, even when ignition is off (white in the loom). the switched 12v was Red in the loom, and Black/Purple in the wires to the pump. I cut this black/purple near the pump, and soldered it direct to the back of the circuit board, and hey presto, the car now starts (and also stops - a bonus!!).

Additional info:
before finally openning the electronics, I checked the circuits with a 'scope. The key sensor seemed to detect the key (a 5v signal with data emitted every time the ignition was turned on). This resulted in 3 equal low going pulses on the signal line at the pump, so at this point I dismissed simple bad connections - probably bad ECU (wrong code to pump). On examination of the circuit revealed by the cutting, the connection I soldered to was connected to a surface mount transistor. This transistor had no volts on it on any pin - I had expected it to be switching +12 to the connection, so it looks like the +12 was not getting through the circuit - maybe a dry joint on the +12v switched input to the circuit.

just left to say thankyou to the designers at Peugeot and Bosch for stealing about 8 hours of my personal time by creating a system so unserviceable!!!
I would say that I would not buy another Peugeot, but it's a bit late, last week (before this failure) I bought a 2003 307 2.0 HDi, and my next job is sorting out DPF 'Anti Pollution Fault'. Looks like I'm going to continue my fun for a few weeks yet .

[teerak2uk]

I think you can get the ecu mapped for dpf removal

[btsimonh]

I have an idea about what caused the immobiliser to kick in.
I've just bought a 2003 307, and one difference I can think of between the day when the car worked, and the day it did not, was that the 307 key was on the keyring used to attempt to start the car. Maybe the key interfered with the 306 key recognition, and caused the system to lock out?
There is no way I can prove this, but it's worth while bearing in mind. If this was the case, I now regret not having disconnected the battery for 10 minutes to see if a full power down restored operation .