The Dispatch | Expert | Scudo Hub

i think we need to start diagnosing why you cant connect to the ecu via the OBD port. it sounds to me like the ecu is not powering up.

**This is what is confusing me, when I plug a scanner in it, itpowers up just won't communicate with the van**

so. my knowledge on these vans is not all that good (yes really).

do you get all lights on the dash come on when you turn the ignition on? including the yellow transistor...  err the thing that looks like a "K" otherwise known as the check engine light?

**I'm not sure on this, I now know which symbol you mean after a quick Google but I don't ever recall seeing it....but I've never looked for it for the last 4 years of trouble free motoring it's been start and go without fail.**

if that lights up it usually means that the ECU is in good order while on ignition only. (seriously try it on other stuff, if you uplug the ecu the check engine light goes out..  its a good way to find out if the ecu has a power issue)
the ECU will still power up even if it has an immobiliser fault..  say the RFID chip in the key stops working. you will still get the yellow "K" looking light

**The immobiliser light is flashing every second or 2 on the dash, once keys are in and turned it goes off....I'm Presuming this is normaly "yes I know your keys" **

one thing to try is a jumper cable clamped to the metal body of the ECU then to the negative battery terminal. this would eliminate any earthing faults.

**I'll give this a go later on this evening as well I've got some small cable knocking about.**

i also would actually unplug the main ecu connectors (with the battery disconnected) to see what the condition of the connectors are like.

**This resolved someone else's same problem the other week I saw the same outcome would be ideal. Vans coming up 20 year old this is going to become common now I think.**

i would also check your ignition switch.. you can test the switch easy. drop the steering wheel down using the adjuster, take off the cowling top cover and you will see the main igntion switch plug.
unplug all connectors with large wires they will be colours like white, blue and i think yellow..  maybe others. they will be the only large wires. 
now make sure you van is in neutral or if you are unsure keep the clutch pressed down because the next step could engage the starter motor.
get a thick ish bit of wire and bridge across the different wires on i think the left side plugs (youll get some little sparks but the power in a car battery is very safe to touch so worry not about electric shocks it wont happen). one will be battery power, one will be ignition switch position 1 (acc), one will be ignition switch position 2 which is glow plug mode/engine run (the one that powers up the ecu), and one will be the starter.
you are effectively bypassing the ignition switch. if you power glow plug mode and the ecu "K" light comes on this is good it means the ecu lives again and the solution is to replace the ignition switch
i repaired a Vauxhall Zafera with this same fault once.. been to 3 separate garages and they diagnosed it with a dead ecu. these "plug in" mechanics only know what an ECU will tell them. you need an old school mechanic.
shame you are not local to me i would have come and had a look..  i really like electrical work on vehicles.

now as far as i know, the ECU does have a relay..  i am pretty sure its commonly referred to as the "glow plug" relay. i have never known one to fail but i guess its a possibility. its located kinda behind the drivers side headlight (if its right hand drive)

i mean you could also test for voltage on a sensor while the ignition is on too. that way we would know if the ECU is functioning. give the mas air flow sensor a unplug and test for voltage on the different pins. one of them (i think there's 4 or 5 on these) will have some kind of voltage on it while the ignition is in glow plug mode. #
to test for voltage use a simple bulb test. get a small wattage bulb like say a side light bulb, earth one side with some wire and the other side will be the testing probe. try not to short anything out with it though..  the ecu does auto kill power to the sensors if it detects a dead short thanfully, it wont burn its self out.
now i think the sensors only work on about 5v so the bulb will only glow a bit..  i could be wrong though i have tested many ecus over the years..  it all merges into one.

**This makes sense and is a good shout, if the power to the ecu is fine but the ecu isn't telling the mag sensor to....sense. Then either the mag sensor is dead or the ECU is a cabbage.**

on some vehicles, pin 1 on the OBD port can be an ignition live but its not standardised. i am not sure if our vans are like this.

i hope some of this helps in some way.

fun fact:  the "K" on the ECU light on our vans is the electrical symbol for a component called a Transistor.

Where is the relay situated, can you get a meter in there to see if there is any power going out to the pump?