P0BB3 code meaning
Hybrid/EV Battery Voltage Sense Y Circuit
Powertrain system Generic code P0Bxx codes Check engine light
What P0BB3 means
P0BB3 reports that the sense lead of channel Y, the twenty-fifth cell group, is no longer properly connected. GM's 16OBDG02 programme does not wait for odd voltages but calculates the resistance of the sense line and fails it above 30.00 in seven of nine samples, which is a one-trip Type A fault; the unit is missing in the table. The 2019 battery energy control module instead looks at the cell voltages themselves, for example 1.3 V between neighbours or a reading below 36 mV while that cell is being balanced, with 0.8 s of failure in 1.6 s. The eAssist mild hybrid sets it as a Type B fault when lines N and N-1 both read under 1.4 V and jump by more than 0.5 V. Low and high monitors for Y are blocked while P0BB3 is active.
P0BB3 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 10 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0BB3
- MIL and high-voltage system warning
- Vehicle may not start in electric mode
- Charging aborted
Common causes of P0BB3
- Most likelyOpen circuit in sense lead Y
- PossibleCorroded or loose terminal raising line resistance at Y
- Less likelyCell monitoring slave board fault on input Y
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 P0BB3 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. |
| B3 | The exact fault in that area. |
What to do next
- Note P0BB3 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 P0BB3
What does P0BB3 mean?
P0BB3 means "Hybrid/EV Battery Voltage Sense Y Circuit". P0BB3 reports that the sense lead of channel Y, the twenty-fifth cell group, is no longer properly connected. It is a generic code, so it means the same on every make.
Is it safe to drive with P0BB3?
Drive gently and only to a workshop. With P0BB3 the car can go into limp mode (reduced power) to protect itself.
Will P0BB3 fail an emissions test?
Yes, it can. P0BB3 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 P0BB3 to fix?
Difficulty: workshop only. A typical repair takes 1 to 10 hours of work. This is a job for a workshop.
Will P0BB3 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.