One problem related to wiring has been reported for the 2003 Mercedes Benz C230. The most recently reported issues are listed below.
Check engine light lead to rough idling and inability to drive vehicle. 2003 Mercedes Benz C230 with 61,650 miles on it. All cam sensors, O2 sensors, maf sensor, engine wiring harness replaced with necessary o-rings at dealer. Car was laid up 5 days and at a cost of $2,500.