Engine Controls - Self-Diagnosis 7-Series V12: Introduction
If no fault codes or only pass codes are present after entering self-diagnostics, proceed to TROUBLESHOOTING-NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).
NOTE:
All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated otherwise in testing procedures.