P0B9B code meaning
Hybrid/EV Battery Voltage Sense T Circuit Range/Performance
Powertrain system Generic code P0Bxx codes Check engine light
What P0B9B means
On the 2012 two-mode trucks sense T is block 20, the last of their twenty nickel-metal hydride blocks, and P0B9B shows how GM handles the missing neighbour: block 20 alone is multiplied by twenty and compared with the pack voltage, and a gap above 70 V in 160 of 170 samples sets the code as Type B. All other channels there use a pair of blocks. On lithium-ion packs the code means that cell T does not follow the pack average: the 2019 hybrid processor demands 0.005 V of movement when the average shifts by more than 0.022 V (35 of 40 samples, Type A), the 2016 Volt the same with a 7 s in 8 s window, and eAssist half the average movement in 20 of 40 samples, Type B.
P0B9B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B9B
- MIL, drivability usually unchanged
- Hybrid assist or EV range slightly reduced
Common causes of P0B9B
- Most likelyChannel T measurement stuck or sluggish
- PossibleBlock 20 voltage diverging from pack voltage on two-mode NiMH packs
- Less likelyFaulty pack voltage reference used for the comparison
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 tWiring harnessBms
What each part of P0B9B 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. |
| 9B | The exact fault in that area. |
What to do next
- Note P0B9B 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 P0B9B
What does P0B9B mean?
P0B9B means "Hybrid/EV Battery Voltage Sense T Circuit Range/Performance". On the 2012 two-mode trucks sense T is block 20, the last of their twenty nickel-metal hydride blocks, and P0B9B shows how GM handles the missing neighbour: block 20 alone is multiplied by twenty and compared with the pack voltage, and a gap above 70 V in 160 of 170 samples sets the code as Type B. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B9B?
Drive gently and only to a workshop. With P0B9B the car can go into limp mode (reduced power) to protect itself.
Will P0B9B fail an emissions test?
Yes, it can. P0B9B 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 P0B9B to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 6 hours of work. This is a job for a workshop.
Will P0B9B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.