Technical Electrical Gremlins in a 2012 Fiat Ducato

[ireland007]

I've had my 2012 Ducato Van for about 2 years and recently started experiencing severe electronic problems.

• Van won't start when turning the key, engine spins but doesn't start.
• Airbag warning lights show.
• Speedometer and RPM needles make a ticking noise and move slightly for a few seconds.
• Hazard lights, brake lights, windshield wipers, and automatic windows are non-functional

There is power going to the fuses in the main fuse box in the engine bay but the relays dont seem to be getting any power which might explain the lack of power to the Dashboard,i.e no power to the radio or hazard lights.The remote central locking does not work either.

I have tested the battery and earth leads and all are good.All the fuses are also fine.

Does any one have any similar experinences and what was the solution,tnx Garry

 

[the green vanper]

Hello,

Looks like water damage due to the ingress through the scuttle tray, a common problem on the x250.

There are several threads on the forum (and others, too) covering how to resolve the cause.

The earth cables on FIATs tend to rot on the inside. You can't see it, it's possible to confirm by measuring the resistance. The body earthing points gets rusty, which also makes the resistance higher.

Have you checked all the earth cables and points?

Here's the eLearn doc on earths and power supplies.

When water gets through the scuttle tray it often goes along the looms to the ECU and the under the bonnet fusebox. Sometimes it gets also to the BCM, which also contains fuses and relays and is located by the driver's external knee. There's also a third fusebox on the bottom of the B-pillar.

I'd start by checking those.

Is the immo light on when you're trying to start the van?

The immobilizer and the majority of the systems you've listed is controlled by the BCM. I'd check if it is powered / earthed properly.

 

[ireland007]

Tnx for the heads up , The immobiliser light is not on the dash, in fact the only light on the dash is the engine management light and the mileage etc is no visible.I did not know about the third fuse box and will check that , there does not appear to be corrosion in the main fuse box in the engine bay but to say the relays there are not getting power suggests thats the source of my problem,Tnx

Hello,

Looks like water damage due to the ingress through the scuttle tray, a common problem on the x250.

There are several threads on the forum (and others, too) covering how to resolve the cause.

The earth cables on FIATs tend to rot on the inside. You can't see it, it's possible to confirm by measuring the resistance. The body earthing points gets rusty, which also makes the resistance higher.

Have you checked all the earth cables and points?

Here's the eLearn doc on earths and power supplies.

When water gets through the scuttle tray it often goes along the looms to the ECU and the under the bonnet fusebox. Sometimes it gets also to the BCM, which also contains fuses and relays and is located by the driver's external knee. There's also a third fusebox on the bottom of the B-pillar.

I'd start by checking those.

Is the immo light on when you're trying to start the van?

The immobilizer and the majority of the systems you've listed is controlled by the BCM. I'd check if it is powered / earthed properly.

e

 

[Communicator]

Tnx for the heads up , The immobiliser light is not on the dash, in fact the only light on the dash is the engine management light and the mileage etc is no visible.I did not know about the third fuse box and will check that , there does not appear to be corrosion in the main fuse box in the engine bay but to say the relays there are not getting power suggests thats the source of my problem,Tnx

e

I am not an expert on the x250, as I own the earlier x244 model. However may I make some general observations.

1. Do carefully examine both main earth connections, including the contact faces on the body. A quick check for the engine block earth below the air filter is to attach a jump cable between an engine lifting lug, and a clean chassis bolt head or similar. The main battery earth under the front floor can become corroded, worth checking.
You will not be able to measure earth strap resistance with a multimeter. A possible check is to measure the voltage across the strap when cranking the engine. Anything over 0.5V and it needs changing. Others may suggest an even lower maximum voltage drop.

2 The third fusebox is optional, for converters use. A basic van may not have it, also it does not contain anthing essential for starting the engine.

3. You state that the relays are not receiving power. What is the evidence for that? There are only two relays to consider when starting the engine. These both in the engine bay fusebox, B001. T10 is the fuel lift pump relay. You should be able to hear the pump running for several seconds, when turning the ignition on. The other vital relay is T09, Main Injection Relay. This relay should operate when the key code has been recognised.

4. If you unplug relays for testing at their sockets you will initiate an alarm that will rquire resetting. A basic code reader will suffice for that. Also in B001. engine bay fusebox, Fiat do not adhere to the Bosch convention of having the relay coil terminal 86 as positive. It can be 85 instead. Look carefully at diagram E1010, attached by @the green vanper.

 

[ireland007]

I am not an expert on the x250, as I own the earlier x244 model. However may I make some general observations.

1. Do carefully examine both main earth connections, including the contact faces on the body. A quick check for the engine block earth below the air filter is to attach a jump cable between an engine lifting lug, and a clean chassis bolt head or similar. The main battery earth under the front floor can become corroded, worth checking.
You will not be able to measure earth strap resistance with a multimeter. A possible check is to measure the voltage across the strap when cranking the engine. Anything over 0.5V and it needs changing. Others may suggest an even lower maximum voltage drop.

2 The third fusebox is optional, for converters use. A basic van may not have it, also it does not contain anthing essential for starting the engine.

3. You state that the relays are not receiving power. What is the evidence for that? There are only two relays to consider when starting the engine. These both in the engine bay fusebox, B001. T10 is the fuel lift pump relay. You should be able to hear the pump running for several seconds, when turning the ignition on. The other vital relay is T09, Main Injection Relay. This relay should operate when the key code has been recognised.

4. If you unplug relays for testing at their sockets you will initiate an alarm that will rquire resetting. A basic code reader will suffice for that. Also in B001. engine bay fusebox, Fiat do not adhere to the Bosch convention of having the relay coil terminal 86 as positive. It can be 85 instead. Look carefully at diagram E1010, attached by @the green vanper.

Tnx , I used a multi meter to check the voltage going into the relays and it is nil, i will try and test the relays you mention for faults.tnx Garry

 

[Communicator]

Tnx , I used a multi meter to check the voltage going into the relays and it is nil, i will try and test the relays you mention for faults.tnx Garry

It may seem a silly question, but what did you connect the multimeter common lead to? The M5 fixing studs for the fusebox cover are isolated. At least one member has tried to use them to connect the meter common to earth.