Non starting 306 1.9D

[xantia_v6]

But not easy on an armoured pump...

[modmytop]

There is no key pad to enter code.
There are 3 wires that enter the armour box (see pics above) where I now believe the stop solenoid lives. Assuming these are all immobiliser related, I would say it is not a simple stop solenoid operated from the ignition, otherwise why armour it.
Never seen any immobilser button by the steering wheel, but will have a look.

Yes good advice from Haynes. Pity it didn't point me to the stop solenoid. Also not easy job when you have to remove pump then armour to get to it.

[modmytop]

As for the 3 wires, I have read that these could be switched 12V, ground and signal. I intend to check for 12V and ground. If these are OK, does anyone know what to look for on the signal wire? Assume it is a coded waveform from the transponder pick up by the ignition barrel. Is there any circuitry between the pick up coil and the pump? I'll have a look in the Haynes...

[xantia_v6]

The red arrow apparently points to the immobiliser button (if fitted)


I have also seen a couple of reports on the web that a locked 306 immobiliser can be reset by disconnecting the battery, then turning the key to the run position before reconnecting the battery.

[modmytop]

No, it is 4 wires to back of pump. My eyes are failing me!

No immob button there I'm afraid.

[modmytop]

Tried the disconnect battery, ignition set to run, reconnect method to reset immob. No change.
Removed the connector that feeds the 4 wires into the back of the pump. From the harness to the connector the wires are coloured white, red green and green/yellow. They change colour from the connector to the pump. The inside of the connector was spotless, no dirt, corrosion.
The circuit diagram in the Haynes for the NAD late 97 shows 4 wires with the above colours going to the 'pump unit - anit theft'.
It describes the wires as follows:
White - Anti start
Red - Anti start
Green - Oil pressure switch
Green/yellow - ground.
Now another diagram shows the oil pressure switch as an open switch to ground. I assume switch is normally open, and when pressure is high enough switch closes and signal is grounded (but I could be wrong!).
Why would oil pressure be used in anti theft?
While cranking, the oil pressure light is on for a few seconds, then goes out. So I assume the switch is operating OK.
I measured the voltage on the 4 wires in the harness side of the connector, with ignition on and off (but not cranking).
Wire Ignition on Ignition off
White 11.4 11.7 (battery volts = 12.5)
Red 12.3 0.06
Green 0.03 0.0
Green/yellow 0.01 0.0
If the Green wire is from the oil pressure switch, it is showing close to 0V when no pressure, so perhaps the switch is normally closed and opens when pressure high enough ?
Unfortunately I don't have a multimeter that measures current via magnetic field coil, as that might tell me if solenoid is being switched or not.
Took key transponder pick up coil off steering column. Lifting cover I can see a PCB with contacts to the coil. All I could do was buzz out the coil. It gave a low resistance, so not open circuit.
Tried to trace wires from pick up module, but they disappear into loom and behind facia.

[xantia_v6]

You have done some good sleuthing. There should also be an ECU somewhere between the transponder and the pump. This needs power via fuses, so something else to check.

[modmytop]

Hi all. Decided to tackle armour with pump still fitted. Probably not best decision.
5 inch grinder across top right edge, front and back edges.
Then used (Lidl bought) Dremel type tool to make horizontal cut.
Have to say pretty impressed with the tool. Thought the little cutting wheels/discs wouldn't last, but because they are thinner than the angle grinder discs you cut less metal. The problem is you have to hold the dremel absolutely vertical. If not, the disc breaks.

After removing top section for a look, decided to cut sides down further. Then used the hole that the immobilizer wires enter to save a bit of cutting. Unfortunately I should have gone a bit lower, as mentioned in a while. After removing this 2nd section, I could see what I assume was the immobilizer module. I hacked into this with hammer and chisel. You work through the circuit board followed by some gelatin like sealant.

This revealed a plastic base held by 2 allen bolts, with a wire visible at the top going behind the plastic (to the solenoid). The hole I made wasn't big enough get this plastic base out, so I hacked at the bottom of it. Then I realized the top half was actually a metal box covered in plastic. It slid towards the hole, but was just slightly too big. So dremel again to cut a bit of the amour around the original immobilizer wire hole. Eventually the metal box slid out to reveal the shut off solenoid.

(Above pic is viewed through mirror)

Red wire from the immobilizer loom, previously measured as switched 12V, connected to solenoid wire. Then she started first turn of the key!

So thanks for the help and patience!

If the solenoid had been faulty, not sure I could get it out without more cutting.
Should have wrapped crimp with insulation tape when I had access.
Need to set cold start cable, as removed this. Note also removed throttle cable and top right fuel line to allow grinder access.

Inlet air pipes look pretty bad. The ones closer to the battery are the worst. Presumably crankcase breather fumes being recirculated through air distribution chamber.

[white exec]

That's some serious bit of 'hacking', of the very physical kind. You certainly did persevere!
Confirms that it isn't the sort of thing even a determined thief would attempt at the roadside - unless a mobile workshop was on hand.
Glad you finally got it started. All you have to do now is make it look decent!
Look forward to a final photo or two.