P0B65 code meaning
Hybrid/EV Battery Voltage Sense I Circuit Low
Powertrain system Generic code P0Bxx codes Check engine light
What P0B65 means
The 2012 GM two-mode hybrids show a detail worth knowing for P0B65: their battery pack control module only declares channel I, nickel-metal hydride block 9, too low when block 9 and its neighbour block 10 both read under 2 V, and only after 15 of 20 samples at 100 ms; the fault is Type B and needs two trips. A single weak block alone therefore does not set it. GM's lithium-ion controllers judge each cell on its own, setting P0B65 at 0.2 V or less held for 1.4 s within 2 s, Type A, as long as no open-line or communication fault has priority. The BAS Plus mild hybrid uses 1.4 V and 7 of 10 samples. In all cases the reading is too low to be a real cell.
P0B65 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 P0B65
- Hybrid system warning and MIL
- Engine runs more often, electric assist reduced
- Limited power in limp mode
Common causes of P0B65
- Most likelyChannel I sense lead shorted to ground or a lower tap
- PossibleConnector fault affecting adjacent blocks 9 and 10 (two-mode)
- Less likelyFailed measuring input in the battery controller
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 iWiring harnessBms
What each part of P0B65 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. |
| 65 | The exact fault in that area. |
What to do next
- Note P0B65 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 P0B65
What does P0B65 mean?
P0B65 means "Hybrid/EV Battery Voltage Sense I Circuit Low". The 2012 GM two-mode hybrids show a detail worth knowing for P0B65: their battery pack control module only declares channel I, nickel-metal hydride block 9, too low when block 9 and its neighbour block 10 both read under 2 V, and only after 15 of 20 samples at 100 ms; the fault is Type B and needs two trips. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B65?
Drive gently and only to a workshop. With P0B65 the car can go into limp mode (reduced power) to protect itself.
Will P0B65 fail an emissions test?
Yes, it can. P0B65 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 P0B65 to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P0B65 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.