What Does P0B1C Mean?
DTC P0B1C indicates the hybrid battery pack voltage sense "C" circuit is reading above the expected range. The BMS has detected an abnormally high voltage from the "C" section of the high-voltage pack, which could signal overcharged cells, a short to voltage in the sense wiring, or a faulty sensor. Overvoltage at the pack section level is a critical safety concern requiring immediate attention.
Safety Warning
Overvoltage in a battery pack section can lead to cell venting, thermal runaway, and fire. The vehicle should not be driven or charged until the root cause is determined. If true overvoltage exists, the vehicle should be parked in a safe, open area.
Common Causes
30%
Short to voltage in the "C" voltage sense circuit wiring
25%
Overcharged cells in the "C" section due to charge balancing failure
20%
Faulty voltage sense tap providing erroneously high readings
15%
BMS internal calibration error or input channel fault
10%
High-resistance connection causing voltage measurement error under certain conditions
Diagnostic Steps
1
Retrieve freeze frame data including SOC, charging state, and pack temperature at fault occurrence.
2
With proper high-voltage PPE, measure actual voltage at the "C" pack section terminals to confirm whether overvoltage is real or a sensor error.
3
Inspect the "C" sense circuit wiring for shorts to battery positive or other high-voltage sources.
4
Compare all pack section voltages via scan tool live data to identify if the "C" section is genuinely higher than others.
5
If real overvoltage is confirmed, investigate the charge balancing system and individual cell voltages within the "C" section.
6
If sensor error is confirmed, test and replace the voltage sense tap or BMS module as needed.
Estimated Repair Cost
$300 - $5,000
Parts + labor, varies by vehicle and location
DTC P0B1C indicates the hybrid battery pack voltage sense "C" circuit is reading above the expected range. The BMS has detected an abnormally high voltage from the "C" section of the high-voltage pack, which could signal overcharged cells, a short to voltage in the sense wiring, or a faulty sensor. ...
The most common cause of P0B1C (Hybrid Battery Pack Voltage Sense "C" Circuit High) is: Short to voltage in the "C" voltage sense circuit wiring
Typical repair costs for P0B1C range from $300 to $5,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Overvoltage in a battery pack section can lead to cell venting, thermal runaway, and fire. The vehicle should not be driven or charged until the root cause is determined. If true overvoltage exists, the vehicle should be parked in a safe, open area.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0B1C to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Hybrid/EV Battery System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
