X5 3.0D Replace ECU

[Oscarguitar]

X is in the main dealer now for full diagnosis. Dreading the call back for some reason. Cost of diagnosis is a full hour labour so not cheap!

Will report back once I know the outcome. Nail biting stuff

[powers1]

Good luck!Hope its just a sensor

[Oscarguitar]

Just spoken the the dealer. They agree that it drives fine. They have identified faults on the stering angle sensor, Gearbox sensor and 4x4 system sensor. No cause found so far. They now want to carry on with the diagnosis (at £148 per hour) to try an establish a cause. They say it could be wiring or could be a control unit. I asked about the Fuel Injection System Error, they say it is related but no cause found. Is there a common link for these systems.

I'll be seriously annoyed if it turns out to be the ECU!

I have agreed to another hour of diagnosis to try and find out what the issue is.

Any ideas from their findings so far?

[Oscarguitar]

I had a thought yesterday after speaking to the dealer again, the Steering Angle Sensor fault and the 4x4 system fault could both be assocaited to the battery change.

When I changed the battery on first start up afterwards I got (as expected) the 4x4 yellow light up which went once I had turned the steering from lock to lock. I knew to do this from a BMW mechanic who came out once when I ran the battery flat when I first had the car and from reading the threads on here about changing the battery.

When I rang the dealer to explain this (and the battery change was detailed in the letter I went through with the service manager and left in the car for the mechanic) the service manager had never heard of the need to turn the sterring to re-set the steering angle sensor.

They could have spent 1 hour on my time chasing a fault that doesn't exist!

All I need them to do if find out the reason for the fact that it will turn over but not start when the <Fuel Injection System> error come up.

Serious discussions needed I think.

[Oscarguitar]

Update,

£260 later and another visit to the main dealer the diagnosis is the DME? (or ECU in laymans terms) This is what the indy told me was faulty after 15 minutes with a multimeter for free!

The part from the main dealer is more expensive, (£1050) however the labour is less! and re-coding comes as part of the deal rather than an extra cost so the actual job (if you leave out the extra diagnosis) is cheaper.

Car is over 5 years old so no chance of input from BMW.

I just hope this is it. I wish I had got that warranty when i was considering it a couple of years ago.

Live and learn! These cars are too expensive to fix without a warranty.

Fingers crossed that it is now sorted!

[bigwave2255]

sorry maybe i,m dumb but im not getting it........what actually was the problem (yeah i got all the stuff about fault codes) and what did you do to remedy it???

[Oscarguitar]

Main dealer traced it to Bus communication errors in the DME (engine management system). They ruled out other potential sources of the error and confirmed the diagnsis from the indy.

I am having the unit replaced today and the car re-coded today if they can get the part in.

[Oscarguitar]

Final Update (I hope)

Finally the X is back. The DDE 7 unit (Diesel Engine Management) has been replaced and installed (part cost £1050 plus fitting and diagnosis). All seems to be working ok so far.

It looks like the sensors were all ok just the part linking them all together and making the decisions was faulty.

An expensive repair but at least I haven't spent months changing sensors and injectors and gearboxes guessing what the real problem was.

I hope my experience will help others.

[Oscarguitar]

Further update

The car has run well since the ECU was replaced. I have to original on my desk as a memento! However it doesn't seem to have as much "grunt" as it used to have. Could this be down to a different or incorrect map (mine should be the 218bhp version not the 186bhp version) being coded with the new ECU. Any thoughs would be useful and any way to check would help as well.

Thanks in advance.

[powers1]

Originally Posted by Oscarguitar

Further update

The car has run well since the ECU was replaced. I have to original on my desk as a memento! However it doesn't seem to have as much "grunt" as it used to have. Could this be down to a different or incorrect map (mine should be the 218bhp version not the 186bhp version) being coded with the new ECU. Any thoughs would be useful and any way to check would help as well.

Thanks in advance.

Hi Oscar,May I ask why only after 3 months do you notice the power difference?
Are you sure that your car wasnt re-mapped prior to the ECU replacement?