Generator Voltage Sense Circuit A Range or Performance
Same as P063A with the sense voltage in plausible range yet not matching the alternator output - high contact resistance or wrong calibration.
Affected components
- Alternator voltage sense a
Common causes
- High likelihood: Contact resistance high
- Low likelihood: Pack cell imbalance approaching service threshold
- Low likelihood: Ground point with elevated resistance
Possible symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.