P063B
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.
Same as P063A with the sense voltage in plausible range yet not matching the alternator output - high contact resistance or wrong calibration.
Common causes
- high
Contact resistance high
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-390
- low
Pack cell imbalance approaching service threshold
Less common, but worth ruling out after the more likely causes.
Typical part cost: $90-390
See all causes + fix costs
Create a free Wrenchify account to unlock the rest for P063B.
Unlock causesFree forever · No credit card
First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
Get the full step-by-step diagnosis
Create a free Wrenchify account to unlock the rest for P063B.
Unlock diagnosisFree forever · No credit card
Related codes
See related trouble codes
Create a free Wrenchify account to unlock the rest for P063B.
Unlock related codesFree forever · No credit card
Frequently asked questions
What does P063B mean?
P063B means "Generator Voltage Sense Circuit A Range or Performance". It is a generic OBD-II code that points to a fault in the computer & auxiliary output controls.
What are the most common causes of P063B?
contact resistance high; pack cell imbalance approaching service threshold; ground point with elevated resistance — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
Get the full P063B diagnosis for your vehicle
Year, make, model + step-by-step repair help — free plan included.