Run Flat Indicator & DSC Failure - Intermittent Fault

[tom2007 1]

Hi Everyone,

I imagine I must take this in to get looked at, however thought it worth seeing if anyone had any suggestions for simple things I could check, before I did that:

I have 2007 BMW325i Motorsport, equipped with i-drive.

Intermittently the following three faults appear (all are present at the same time, or absent at the same time). There is no real ryhme or reason to when they appear, sometimes I will start car and they are present, sometimes they are not. Sometimes it will appear while I am driving, sometimes disspear while I am driving.

1. - ! RUN FLAT INDICATOR 'Run flat indicator failure. Tyre punctures cannot be identified' [Appears on i-drive screen and orange warning appears in center of dash]

2. - ! DSC FAILURE 'Driving stability affected when cornering and accelearating. Drive at moderate speeds, cornering and accelerating. [Appears on i-drive screen and orange warning appears in center of dash]

3. - Left and right turn indicators will not turn itself off, after completing corner, have to manual turn off.

Handling doesn't seem to be affected, though am not sure if the DSC really is not working, or if it just says that.

Am wondering is there a chance this is a mechanical, or connection fault, rather than something in software?

If it was likely a connection, given the above, are there any logical places to look?

Thanks in advance, if anyone has any suggestions.

Cheers

Tom

[*Glenn* 854]

From your description I would guess at a sensor/sensors/software fault... It needs to be scanned and diagnosed correctly. What area do you live in ??

Edited June 27, 2010 by *Glenn*

[tom2007 1]

From your description I would guess at a sensor/sensors/software fault... It needs to be scanned and diagnosed correctly. What area do you live in ??

Hi Glenn, Thanks very much. Cheers, Tom (Am in Auckland City)

[pureboiracer 0]

check tyre pressures... they can do all sorts....

[*Glenn* 854]

Tyre pressures can cause the 1 & 2 but the 3rd fault is something quite different. If the tyre pressures are right it may have other problems and it will need to be diagnosed properly.

[jochen 4]

Tyre pressures can cause the 1 & 2 but the 3rd fault is something quite different. If the tyre pressures are right it may have other problems and it will need to be diagnosed properly.

Hmmm... does the vehicle calculate the rate of turn from the difference in speed of the front wheels, and then cancel the indicator when the turn is complete?

That would indicate one of the front wheel speed sensors is not working, and that would be a commonality for all 3 symptoms

I would place my bets on an intermittent connection on a front wheel sensor, or a bad sensor.

Make sure the wheel sensor plate / disc is clean, and check integrity of the front wheel sensors...

[*Glenn* 854]

It should have active steering with a steering angle sensor.. I don't have a chassis # to check ETK & TIS

[tom2007 1]

Thanks Oli, Glenn, Jochen -

That's really interesting. In first instance I'll check tyre pressures and let you know if that made any difference to anything. Glenn, will dig up chassis # and send you.

Thanks again everyone.

Cheers,

Tom

Edited July 6, 2010 by tom2007

[tom2007 1]

Hmmm... does the vehicle calculate the rate of turn from the difference in speed of the front wheels, and then cancel the indicator when the turn is complete?

That would indicate one of the front wheel speed sensors is not working, and that would be a commonality for all 3 symptoms

I would place my bets on an intermittent connection on a front wheel sensor, or a bad sensor.

Make sure the wheel sensor plate / disc is clean, and check integrity of the front wheel sensors...

Hi Jochen, To do this, would just remove front wheels and ensure brake discs are clean?

Do you mind briefly describing what sensor would look like and location? (Sorry I am a moron!)

Cheers,

Tom

[tom2007 1]

It turns out that tyre pressure was low on all 4 tyres (28-30psi instead of the recommended 38 psi). Filled them back to 38 psi, but the problem persists. I think Glenn your original advice is right, and have to take it in and get diagnosed.

[tom2007 1]

In case anyone's interested. I took the car in to get diagnosed and repaired. The cause of this actually turned out to be faulty active steering unit. This was replaced and now all faults have disappeared. Thanks, everyone for your input. Cheers.