Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer thinks the battery is showing a voltage that's too high to be real. It's like if a thermometer said it was 200 degrees outside when it's really only 70 degrees.
The vehicle's control module has detected an unusually high voltage reading from the 'C' circuit of the hybrid or electric vehicle battery sensor.
The P1B9B code is set when the powertrain control module (PCM) detects an implausible high voltage reading from the voltage sensing circuit 'C' of the hybrid/EV battery. This could indicate a fault in the sensor, wiring, or the battery itself.
• Check Engine Light illuminated
• Reduced fuel efficiency
• Possible reduced power or performance
• Faulty battery voltage sensor
• Damaged or corroded wiring/connectors
• Faulty hybrid/EV battery
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code.
• Inspect the battery voltage sensor and its wiring for damage.
• Test the hybrid/EV battery voltage levels.
• Replace the faulty battery voltage sensor.
• Repair or replace damaged wiring/connectors.
• Replace the hybrid/EV battery if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $1000
Moderate
• Toyota Prius
• Chevrolet Volt
• Nissan Leaf
• Regularly inspect battery connections.
• Ensure battery sensors are functioning correctly.
• Perform routine maintenance checks.
Sensor Issue
• Avoid driving at high speeds until the issue is resolved.
• Schedule a service appointment with a qualified technician.
Check vehicle warranty for coverage on hybrid/EV components.
This code has been more prevalent in older hybrid models as battery sensors age.
Moderate – Should be addressed soon to prevent potential battery damage.
Driving with a malfunctioning battery sensor can lead to reduced vehicle performance and efficiency.
• Vehicle must be in a safe, stationary position.
• Battery should be fully charged for accurate testing.
The battery voltage sensor is typically located near the hybrid/EV battery pack.
Q: Can I drive my car with this code?
A: It's possible, but not recommended as it can lead to reduced performance and efficiency.
Q: How can I reset the code?
A: Fix the underlying issue first, then use an OBD-II scanner to clear the code.
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