P063B Generator Voltage Sense Circuit Range/Performance

Definition: The P063B code indicates that the Powertrain Control Module (PCM) has detected a problem with the generator voltage sense circuit. This could mean that the voltage is outside of the expected range or that there is a performance issue within the circuit.

p063b – Generator Voltage Sense Circuit Range Performance

Typical severity: Moderate

Common Causes

p063b – Generator Voltage Sense Circuit Range/Performance

Common causes:

• Faulty generator voltage sensor
• Wiring issues in the generator voltage sense circuit
• Loose or corroded electrical connections related to the generator voltage sensor
• Generator failure or malfunction

 

Common Misdiagnosis

OBD2 Code: P063B

Description: Generator Voltage Sense Circuit Range/Performance

Common Misdiagnosis: Replacing the alternator or battery without checking for wiring issues or poor connections in the voltage sense circuit.

 

Common Diagnostic Steps

OBD2 Code: P063B

Description: Generator Voltage Sense Circuit Range/Performance

Common Diagnostic Steps:

• Check the battery voltage and ensure it is within the manufacturer’s specifications.
• Inspect the generator (alternator) connections for corrosion, damage, or loose connections.
• Test the generator output using a multimeter to verify proper voltage levels.
• Examine the wiring harness and connectors related to the generator circuit for any signs of wear or damage.
• Use a scan tool to monitor live data from the charging system and compare it with expected values.
• Verify that all related fuses are intact and functioning correctly.
• If applicable, check for any Technical Service Bulletins (TSBs) related to this code for specific vehicle models.
• If no issues are found in previous steps, consider testing or replacing the voltage regulator if it’s separate from the alternator assembly.