My 2005 645 convertible with only 12,000 gentle miles is throwing random Dynamic Drive Warnings.

Last week, I had my independent mechanic read the codes stored in the ARS control unit. They read 5D5B (pressure build up front axle), 5D5C (pressure sensor rear axle) and 5EF5 (pressure sensor rear axle).

BMW issued a SIB on the issue SI B 37 200 04 (Below)

ARS Fault Codes 5D5B or 5D5C

Customer complains of Dynamic Drive Failure.

Faults codes 5D5B (pressure build up front axle) or 5D5C (pressure sensor rear axle) may be stored in Active Roll Stabilization (ARS) control unit.

Low fluid level, damaged hydraulic lines, faulty front sway bar or faulty power steering pump may cause these faults.

Check the ARS fluid level and system pressure.

* Ensure power steering fluid is at proper level.
* If system pressure goes above 150 bar, then replace the front sway bar.
* If system pressure does not go above 150 bar, then check the hydraulic supply lines for damage.
* If hydraulic lines are not damaged, then replace the power steering pump.

I had the independent shop clear the codes, but the Dynamic Drive warning appeared again over this weekend.

This morning, I took the 6 to my local dealership for a full diagnosis. The SA is offering to replace the Dynamic Drive block at a cost of $2,100. When I challenged the SA as to whether this would guarantee the fix, especially since replacement of the block was not listed in the SIB, he said he would have the technician re-confirm the diagnosis.

I purchased the 6 in a private sale with only 1,200 miles June 2008 and have driven every mile since. I'm meticulous about maintenance and have every maintenance record, including those from the previous owner. I'm obviously out of the manufacturers warranty coverage. With 12,000 miles, I fail to understand how the vehicle could have such a significant mechanical breakdown that is also a potential safety hazard. I asked the SA as to whether BMW would consider a goodwill warranty repair - no luck thus far.

Anyone have any ideas. Cobradav - you are the most educated and seasoned owner among us... have you experienced the Dynamic Drive failure, any advice on how to request a goodwill warranty repair?