P0B9C code meaning
Hybrid/EV Battery Voltage Sense T Circuit Low
Powertrain system Generic code P0Bxx codes Check engine light
What P0B9C means
P0B9C signals that sense T reads too low. On the 2012 two-mode trucks this is block 20, and because no block 21 exists the low test there looks at block 20 alone: below 2 V in 15 of 20 samples, Type B, while channels R and S each need their upper neighbour to read low as well. GM's lithium-ion controllers from the 2016 Volt to 2019 work with 0.2 V or less for 1.4 s within 2 s, Type A, the 16OBDG02 programme with under 0.20 V in 14 of 18 samples, and the eAssist mild hybrid with 1.4 V in 7 of 10 samples, Type B. Open sense line faults are evaluated first. For the driver the result is a warning and reduced power until the cause is repaired.
P0B9C 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 P0B9C
- MIL and hybrid warning
- Reduced power, engine may not shut off on hybrids
Common causes of P0B9C
- Most likelySense lead T shorted to ground or a lower potential
- PossibleWeak or discharged NiMH block 20 on two-mode packs
- Less likelyFailed measuring input for channel T
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 P0B9C 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. |
| 9C | The exact fault in that area. |
What to do next
- Note P0B9C 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 P0B9C
What does P0B9C mean?
P0B9C means "Hybrid/EV Battery Voltage Sense T Circuit Low". P0B9C signals that sense T reads too low. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B9C?
Drive gently and only to a workshop. With P0B9C the car can go into limp mode (reduced power) to protect itself.
Will P0B9C fail an emissions test?
Yes, it can. P0B9C 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 P0B9C to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P0B9C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.