Automotive electrical diagnosis is a professional testing method for faults in vehicle electrical systems, primarily involving locating problems through systematic processes and specialized tools. For example, when a battery is discharged, the static voltage needs to be tested (charging is required if it is below 11.8V), while for CAN bus faults, terminal resistance (normal value is 60Ω) or waveform distortion needs to be checked. Diagnosis must comply with safety regulations, such as disconnecting the negative terminal of the battery before operation, and high-voltage systems in new energy vehicles require handling by professionals with relevant qualifications. In a broader context, modern automotive electronic systems are highly complex, involving ECU networks (such as engine control modules) and ADAS, which require technicians to master the ability to interpret circuit diagrams and analyze data streams. For instance, a stagnant oxygen sensor signal may cause abnormal fuel consumption, which requires comprehensive judgment combining a diagnostic scanner and dynamic testing.
