Technical 2002 ducato code immobiliser light wont go off

[Sean86]

Problem started as an intermittent issue
The code light would come on and go out like normal then it would stay on, then if i cycle the ignition it usual go's out and operates correctly.
I have had to cycle the ignition more times sometimes upto 10 recently.
But now it's on permanently. Here's what I have tried

2002 2.8JTD fiat motorhome
3pin OBD wire
X2 blue keys with chips and both work.

Tried both keys with same fault.
I checked the transponder ariel and all looks ok wires/pins, with around 30ohms resistance.
The yellow immobiliser box connections all good
I have x2 pins for the aerial on one connector to box and 5 pins on the other connector to the immobiliser box.

The 5 wires
Black = ground
Yellow-blue = code light on combination meter
Red = jumped onto 12v wire in the loom
Orange = goes to fuse box (fuse ok and replaced)
Pink = goes to Engine ECU
What should I check on these wires ?
What should there reading be?


If I back prob the pink wire at yellow immobiliser module

Wire unplugged
Ignition on = 5v

Wire plugged in 10v with immobiliser code ON
Wire plugged in 12v with immobiliser code OFF
So when system is deactivated the voltage increases ?
(Recognised)
....
I have tried having ignition on and wiggling all the wiring loom and connectors and no different.
I have checked the fuel cut switch and its all ready pressed down.

my immobiliser is all electrical doesn't have the fuel pump mechanism like the older ones.
So I can see lots have had the same or similar issues and have opted to remove the immobiliser soni removed the Engine ECU , yellow immobiliser Module, aerial, and x2 blue keys off to have the immobiliser put in immobiliser off mode by a specialist. They said they could see the immobiliser data was ok but not sure why its not communicating ok so they suggested to remove the immobiliser from the system. They said the EML might come on as a consequence but the vehicle will start. So I said do it.

Fitted the parts and boom exactly same issue the code light is on and says NO.

I'm confused how can I still be locked out by the Immobiliser if its been disabled.
So I called them and they said they will have to get the engineer to have another look. So I sent it back and a few days later that say its all in immobiliser off mode we have done it and advised me to make sure the engine ecu is communicating with the module via a scanner and see if any codes.
I have the 3pin connector so plugging in isn't that easy I have the adapter wire and an old diag computer and had no joy connecting to it before. But I will Try again .

Don't know if anyone could give some guidance.

Also the other day I had the dashboard out with all components connected with code light ON just sitting there then without moving anything the code light when off and the van fired up. I turned it off back on and code light ON again. So seems not a connection issue ? if nothing was moving?
Also I found these marks inside the yellow immobiliser module looks like circuit board damage to me but they said the engineer had checked and all ok and said its just felt tip pen..

I'm getting the parts back tomorrow and will continue the headache. And check that board out, i wonder if there's a blown component underneath the dark parts.

Do these immobiliser systems use any relays ?
Oh and I live in this full time so very inconvenient.

Appreciate anyone taking the time to read this

Sean

 

[Sean86]

Also thinking of buying this diag machine I see others have been able to talk to the 2.8jtd with this device but not sure if it will talk to the immobiliser, it doesn't say it does but on one of the reviews an image of the device on diagnostic screen shows option for
Immobiliser ( embedded in the engine)
So mabey it does anyone know.
Its £120 if I can save on a call out to have vehicle codes scanned and do myself would be good.

Sean

 

[Sean86]

Also thinking of buying this diag machine I see others have been able to talk to the 2.8jtd with this device but not sure if it will talk to the immobiliser, it doesn't say it does but on one of the reviews an image of the device on diagnostic screen shows option for
Immobiliser ( embedded in the engine)
So mabey it does anyone know.
Its £120 if I can save on a call out to have vehicle codes scanned and do myself would be good.

LAUNCH Diagnostic Tool Creader VII+​

Sean

 

[Communicator]

Hi Sean,

You added a post #17 to the thread "fiat ducato 2.8d key code stays on so won't start?" at 10:43pm yesterday. I requested the engine type at 11:04pm, but you do not seem to have had the courtesy to reply.

However you have now posted vehicle details in this thread.

Your symptoms suggest a gradual weakening of the signal received from the key when interrogated by the code receiver at ignition on.

When faced with a similar problem about a year ago with 2 out of 5 (40%) failures, I reasoned that the radio signal from the key was insufficient to breakthrough any oxide film at the aeriel connection to the code receiver. I unplugged both of the code receiver onnectors and applied contact cleaner for good measure. So far no further problems, but the vehicle has only been lightly used.

 

[Ocwobio]

Is the battery really beyond suspicion? These things simply must have a very good battery, to avoid any electronic shenanigans on starting. Regarding Communicators advice regarding contact cleaner, the best out there is Deoxit, but it's expensive. Check that the battery is very fully charged, nearer to 13 v the better. Check/replace/supplement the battery earth strap, a jumper lead is fine for temporary use. Try turning on the ignition a few times without starting, waiting for the dash lights to go out before starting is a good idea. Forget Launch, it doesn't speak fluent Fiat, get MultiEcuScan on an old laptop, but use a quality lead.(The demo download may work but is time limited, IIRC 2o minutes). Not a bluetooth dongle. Keep any mobile phone and other car keys away from the driers seat area while trying, just in case.

 

[Sean86]

Appreciate the feedback here's the update

I got the parts back yesterday plugged them in all all working correctly now. I have been cycling the ignition and works everytime. Too scared to go for a drive yet but did move about in a little car park parked back up and all still operating correctly.

The only thing I did do while waiting for the parts was relook at the back of the combination meter plug where the code signal wire goes and it has the circuit board printed on plastic that connects to the plug. I found hard to separate the connection but it came part I checked the connection the code wire all ok but I found the ground wire connection was bad the plastic had been crumbled and made the connection bad I re positioned and fitted the plug back on.

Mabey thay had something to do with it.
Also when I had the problem when I turned the ignition on my air conditioning compressor clutch would engauge every time but now my code light goes out the clutch does not engage like it shouldn't.

How could the a/c clutch and immobiliser be closely connected. I don't know but was definitely linked together.

I Will monitor and update in a few days

And appreciate the help

Sean

 

[Ronnie63]

I had that issue with the imobiliser light staying on and would crank but not start, I also noticed that the hazard lights did not work either, turned out it was a fuse! Mine also a 2002 Ducato but 2.0jtd

 

[Communicator]

I had that issue with the imobiliser light staying on and would crank but not start, I also noticed that the hazard lights did not work either, turned out it was a fuse! Mine also a 2002 Ducato but 2.0jtd

Ronnie63,

Is your vehicle an x230, or an x244? 2002 was changeover year, and wiring is different between models.

 

[Ronnie63]

Ronnie63,

Is your vehicle an x230, or an x244? 2002 was changeover year, and wiring is different between models.

Yes x230 just prior to changeover