What do these error codes mean?

[Ballapaddag]

I have a 2005 CDTI with BMW engine.
Has developed a weird electrical fault.
Diagnostics return F8, F6 & F2 Data Error from DHE / DDE

Contacted Rimmer Bros for advice re replacement part but they have no idea what this means.

What is DHE / DDE please? Is it the ECU ?

[BigRuss]

The error codes don't mean anything to me either they aren't the usual P codes.

The DDE is the engine ECU

What kind of problems are you having?

Russ

[Ballapaddag]

Originally Posted by BigRuss

The error codes don't mean anything to me either they aren't the usual P codes.

The DDE is the engine ECU

What kind of problems are you having?

Russ

Thanks Russ,
Bizarre behaviour.
Dashboard indicator lights not working but working on the outside of the vehicle.
Climate Control switches on but in two seconds = Er.
Remove ignition key, lock the car and after a few minutes windscreen wipers start on their own, even though switched off

Garage has checked for chaffed wires etc but all appears OK. The codes are from their Diags tool but the problem was identifying the meaning of the error

[BigRuss]

The problems that you describe are usually down to a K-bus error

It is unlikely that be your engine ECU (DDE) is causing this but check to see if there's water in the plenum that's affected it just in case.
Forget the codes from the garage they probably mean that their diagnostics won't talk to the DDE

Has there been any water inside the car at all?

Russ

[Ballapaddag]

Originally Posted by BigRuss

The problems that you describe are usually down to a K-bus error

It is unlikely that be your engine ECU (DDE) is causing this but check to see if there's water in the plenum that's affected it just in case.
Forget the codes from the garage they probably mean that their diagnostics won't talk to the DDE

Has there been any water inside the car at all?

Russ

Thanks again Russ,
No water in the car. Is totally dry and Plenum ECU is dry. ( Check it regularly )
I did some previous research and also came across the K-Bus reference as a possible cause but could not understand the meaning.
Could you explain what is the K-Bus? Is it a component or an integral part of the vehicle or what?
Is it replaceable /serviceable.

If it is something that can be inspected / tested then where is it ?

All a bit of a new science to me

Regards

Mick

[suzublu]

Fitted a radio recently?

[BigRuss]

That's ok, not many do usless you work with automotive wiring systems.

There are several Data buses on our cars think of them as a network cable linking the Ecu's together they transmit data messages between them to cut down on wiring.

The main one is Can-bus and links the more important systems, Engine ECU, ABS ECU, Instrument pack and Auto box if fitted.

The next is K-bus, carries less important information, and links not only some of the main ECU's above but also all the others, Airbag, Instrument pack, Audio, light switch, parking sensors, FBH, Sat nav, Body control unit, rain sensor, Video and radio modules, Immobiliser, seat memory ECU's (Depending on spec of car)

In each of these is a K-bus controller that recieves and or sends information, if one of these goes faulty or if the wiring to it is damaged or shorting then it can cause the issues that you describe.

The K-bus is a single red/white wire with yellow bands every 4cm that are connected to each ecu, they join at a header behind the dashboard, note that at the header the wiring colour is red/white without the yellow bands

To isolate the fault it can be sometimes useful to disconnect the ECU's one at a time (not the instument pack) to see if there's a faulty K-bus controller that's causing it. If after checking that the fault remains then it's likely to be a K-Bus wiring issue.

Has you car got high line nav system or a fbh? If so try disconnecting those first

Russ

[BigRuss]

Originally Posted by suzublu

Fitted a radio recently?

Yes good point Ronnie

Many times in the past similar problems have occured when something has been added to the car.
If it has had something added, undo what has been done and see if the faults disappear

Russ

[Ballapaddag]

Originally Posted by BigRuss

That's ok, not many do usless you work with automotive wiring systems.

There are several Data buses on our cars think of them as a network cable linking the Ecu's together they transmit data messages between them to cut down on wiring.

The main one is Can-bus and links the more important systems, Engine ECU, ABS ECU, Instrument pack and Auto box if fitted.

The next is K-bus, carries less important information, and links not only some of the main ECU's above but also all the others, Airbag, Instrument pack, Audio, light switch, parking sensors, FBH, Sat nav, Body control unit, rain sensor, Video and radio modules, Immobiliser, seat memory ECU's (Depending on spec of car)

In each of these is a K-bus controller that recieves and or sends information, if one of these goes faulty or if the wiring to it is damaged or shorting then it can cause the issues that you describe.

The K-bus is a single red/white wire with yellow bands every 4cm that are connected to each ecu, they join at a header behind the dashboard, note that at the header the wiring colour is red/white without the yellow bands

To isolate the fault it can be sometimes useful to disconnect the ECU's one at a time (not the instument pack) to see if there's a faulty K-bus controller that's causing it. If after checking that the fault remains then it's likely to be a K-Bus wiring issue.

Has you car got high line nav system or a fbh? If so try disconnecting those first

Russ

Thanks Russ,
That is a brilliant explanation and I will pass this onto the garage as it is now beyond my experience and knowledge.
Nothing added to the car at all. Exactly " as is" and has been for years. It does have the high live nav system so will suggest this as a possible cause.
Many thanks again for your time and input.

[BigRuss]

Thanks, as you've got high line nav I'd try disconnecting the Video module first, it's the one on the left when the black plastic cover in the spare wheel well is removed.

They can and do go faulty and can cause the same kind of problems

Russ