Northern Auto Tech - ECU and Blue & Me Repairs

Technical Imobilser

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Technical Imobilser

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duckdriver

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Hi Guys

After a little help with the imobiliser fitted to my 2003 2.0JTD Ducato.

I'm wondering how I will know if I have an issue with it - how exactly does it stop the engine from starting, is it something to do with the fuel, electrics etc?

I dont have an issue with it as yet, but every now and again I get an imobiliser warning light come on!
 
Yes both keys - I did have a non starting issue a week or so ago, that was causing all the fuel in the HP pump to bypass and go to return - the problem magically went away all of its own - now I'm starting to think that the imobiliser some how by passes the fuel pump?!?
 
You need to stop thinking about it like an old engine with immobiliser active you might as well have no engine all that happens is the starter relay engages the starter and turns the engine the ecu does nothing no sensors are read, no actuators are actuated. The fuel circulating to return is because the pressure regulator is not operating. Its like if you remove the CPU from your computer it will turn on and flash or beep that there's no CPU but that's all it does.

The only thing you can DIY without a lot of knowledge and specialist equipment is clean the contacts on the Immobilizer unit (battery disconnected for 15mins before fiddling) failing that try a new key antenna from a scrap yard or ebay. If you still have an issue your only other practical DIY option is swap a complete set of ecu immobiliser and keys from another vehicle. Otherwise your looking at dealer or an autolocksmith that will reprogram a new immobiliser unit from the contents of your old one or an auto electronics person to transfer your old immobiliser eeprom to a new/secondhand immobiliser unit.
 
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Just reading your thread and came across the attachment by Moodrater....wow that's some article. Does this apply to the 2.8JTD engine as well? Always wanted to read what goes on in the engine.
Hope you get your problems sorted duckdriver.
 
Hi. Does the 2007 Miltijet model work the same way? Mine having loads of non starting days due to padlock light staying on. Doesn't matter which key I use.
 
r1c1 said:
Hi. Does the 2007 Miltijet model work the same way? Mine having loads of non starting days due to padlock light staying on. Doesn't matter which key I use.
Click to expand...

Your soaked wiring is the source of your problems I'd say when you fix that you should look for solutions to the water ingress so that you don't end up with more problems.
 
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moodrater said:
You need to stop thinking about it like an old engine with immobiliser active you might as well have no engine all that happens is the starter relay engages the starter and turns the engine the ecu does nothing no sensors are read, no actuators are actuated. The fuel circulating to return is because the pressure regulator is not operating. Its like if you remove the CPU from your computer it will turn on and flash or beep that there's no CPU but that's all it does.
Click to expand...

Thanks for your post Mood, but in this case I do believe that you are slightly off the mark! The van has gone off to a diesel specialist yesterday, and along with it went the catalogue of work that I carried out on it, and they can find no fault with either the fuel pressure regulator (both old and replacement) nor can they find fault with either HP pump (old and new both bench tested) and nor is the signal being provided by the ECU incorrect for the pressure regulator - the injectors are getting a low voltage, but this could be because the logic circuit controlling them is not being given the right input from the rail pressure sensor as there is no rail pressure!

Garage suspect a low pressure fuel delivery issue, as there is a cascade overflow valve inside the Bosch Pump which needs to hit 3bar before it begins to open - who knows??????????:bang:
 
I'm not saying theres anything wrong with your regulator, I'm saying that if your immobiliser is active the ecu will not do anything with it or the injectors.

This is the question I was answering:
duckdriver said:
now I'm starting to think that the imobiliser some how by passes the fuel pump?!?
Click to expand...

The high pressure is set by varying the duty cycle of the high pressure regulator, 0 duty cycle - 0 pressure. At starting the ecu sets the duty cycle to something like 40% to put pressure in the rail. The correct signal would be determined by looking at it with a digital oscilloscope.

I assume your immobiliser was off and the diesel specialist used an oscilloscope when they were looking at it otherwise I think you're dealing with the wrong people.
 
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Hi mood, sorry my misunderstanding!

To be totally honest, I don't think they have scoped the pressure reg voltage, but I am not impressed with the current garage, so a recovery agent is picking the car up tomorrow to take it to a place near jct2 of the m5 in brum!
 
Good luck, hard to find someone that knows enough, my neighbour is newly qualified as a hgv mechanic he said he learned more about electronics from the dodgy characters on day release from prison than the lecturers. Its hard to keep up. I recently brought my diesel pump to a registered bosch place to be rebuilt and the young guy that was supposed to do the job didn't know if it was a cp1 or a cp3 pump. I advised him to bring the book home and do some reading and I'd come back in a few years lol.
 
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