P0BB5 code meaning
Hybrid/EV Battery Voltage Sense Y Circuit Low
Powertrain system Generic code P0Bxx codes Check engine light
What P0BB5 means
P0BB5 stands for a sense Y voltage below the plausible minimum. GM's 2016 Volt module and the 2019 battery energy control module both use 0.2 V or less for 1.4 s inside a 2 s window and flag it as Type A. Before testing, the 2019 module makes sure that no open sense line, no lost communication with the cell monitoring slave and no balancing or internal slave fault is active, and that the second protection self test is not running. The eAssist mild hybrid sets the code below 1.4 V in seven of ten samples, Type B. The likely culprits are a pinched sense wire touching a lower potential, a failed measuring channel or a cell that has really lost its charge. The driver sees a warning and reduced performance.
P0BB5 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0BB5
- Hybrid or EV warning with MIL
- Noticeably reduced power
Common causes of P0BB5
- Most likelyPinched sense wire Y shorting to a lower potential
- PossibleFailed measuring channel Y
- Less likelyCell Y severely discharged
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery voltage sense yWiring harnessBms
What each part of P0BB5 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. |
| B5 | The exact fault in that area. |
What to do next
- Note P0BB5 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 P0BB5
What does P0BB5 mean?
P0BB5 means "Hybrid/EV Battery Voltage Sense Y Circuit Low". P0BB5 stands for a sense Y voltage below the plausible minimum. It is a generic code, so it means the same on every make.
Is it safe to drive with P0BB5?
Drive gently and only to a workshop. With P0BB5 the car can go into limp mode (reduced power) to protect itself.
Will P0BB5 fail an emissions test?
Yes, it can. P0BB5 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 P0BB5 to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P0BB5 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.