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 your car's computer has detected a problem with the battery's voltage sensor. It's like when a toy's battery checker says the battery is low, but it might not be true.
The vehicle's control module has detected a low voltage signal from the battery voltage sense circuit B, which could indicate a problem with the sensor or wiring.
The P0B42 code is triggered when the Powertrain Control Module (PCM) or Battery Energy Control Module (BECM) detects that the voltage level from the Hybrid/EV battery voltage sense circuit B is lower than expected. This could be due to a fault in the sensor, wiring, or connectors.
• Check Engine Light is on
• Reduced fuel efficiency
• Possible battery charging issues
• Faulty battery voltage sensor
• Damaged or corroded wiring/connectors
• Faulty Battery Energy Control Module (BECM)
PCM: Powertrain Control Module
BECM: Battery Energy Control Module
• Use an OBD-II scanner to confirm the code.
• Inspect the battery voltage sensor and its wiring for damage.
• Check connectors for corrosion or loose connections.
• Replace the faulty battery voltage sensor.
• Repair or replace damaged wiring/connectors.
• Replace the Battery Energy Control Module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Toyota Prius
• Chevrolet Volt
• Nissan Leaf
• Regularly inspect battery and wiring for damage.
• Ensure connectors are clean and secure.
• Perform routine maintenance as per the vehicle's schedule.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Avoid driving long distances until the issue is resolved.
Check with your vehicle manufacturer as hybrid components often have extended warranties.
This code has become more common with the increase in hybrid and electric vehicles, highlighting the importance of battery maintenance.
Moderate – While not immediately dangerous, it can affect vehicle performance and efficiency.
Driving with a malfunctioning hybrid battery system can lead to reduced performance and efficiency. Always address warning lights promptly.
• Vehicle in 'ready' mode
• Battery at normal operating temperature
The battery voltage sensor is typically located near or on the hybrid/EV battery pack.
Q: Can I drive with a P0B42 code?
A: It's not recommended to drive long distances as it can affect performance and efficiency. Have it checked soon.
Q: How do I clear the P0B42 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue persists, the code will return.
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