P0B1B code meaning
Hybrid/EV Battery Pack Voltage Sense C Circuit Low
Powertrain system Generic code P0Bxx codes Check engine light
What P0B1B means
P0B1B sets when pack voltage measurement C delivers a reading below its plausible lower limit. Typical electrical causes are a sense lead shorted to ground, an open fuse or resistor in the sense path, or a defective controller input. No manufacturer documents this code publicly. GM applies the same idea to channel A, where P0ABC sets below 24 V pack-side voltage for 1.6 s in a 2 s window, Type A. CARB calls for out-of-range monitoring of battery voltage sensors. The high counterpart is P0B1C and the plausibility code P0B1A. A pack voltage reading that is too low can prevent precharge and contactor closing, so the vehicle may not become ready to drive.
P0B1B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B1B
- Vehicle may not reach Ready or may shut down the high-voltage system
- MIL and hybrid/EV system warning on
- Battery power limited, reduced electric drive or assist
Common causes of P0B1B
- Most likelySense lead of channel C shorted to ground
- PossibleFuse or resistor in the sense path open
- PossibleMeasurement input of the battery controller defective
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery pack voltage sense cWiring harnessBms
What each part of P0B1B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| B | Area: hybrid propulsion. |
| 1B | The exact fault in that area. |
What to do next
- Note P0B1B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0B1B
What does P0B1B mean?
P0B1B means "Hybrid/EV Battery Pack Voltage Sense C Circuit Low". P0B1B sets when pack voltage measurement C delivers a reading below its plausible lower limit. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B1B?
Drive gently and only to a workshop. With P0B1B the car can go into limp mode (reduced power) to protect itself.
Will P0B1B fail an emissions test?
Yes, it can. P0B1B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0B1B to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P0B1B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.