TSB: BMW Belt Drive

This bulletin applies to 2023 BMW X5 and X6 Sports Activity Coupe and X7 Sports Activity, 3 Series Sedan, 4 Series Coupe, 5 Series Sedan and 640I xDrive Gran Turismo.....equipped  with the B58C/D and 48V system.

The check control message (CCM) may indicate ID 213...(stop, exercise due care, voltage supply). The Service Engine Soon light may be on with DME fault code 21B209 (starter alternator/ belt for 48V system (belt may be torn).

One or more of the following issues may be present:

• Noise in the belt drive area
• Engine compartment odor
• Smoke present in the belt drive area
• Drive belt damaged, torn or worn

Check the alignment marks on the belt tensioner. The black mark on the tensioner needs to be centered in the adjustment window.  Inspect the belt. Using a mirror, check the index number of the crankshaft damper. Replace the damper if it has an index number 01. Inspect the pulley on the starter generator for tightness.

If the retaining screw for the hex nut on the SGR drive pulley is loose or missing, replace the starter generator. If the retaining screw is tight, check the pulley grooves for belt material and clean if needed. Check that the SGR pulley spins freely. Check the water pump pulley for binding If there is any issue with the AC compressor or damaged/leaking pulley, replace the AC compressor.