P0B48 code meaning
Hybrid/EV Battery Voltage Sense C Circuit High
Powertrain system Generic code P0Bxx codes Check engine light
What P0B48 means
No healthy lithium-ion cell reaches 4.8 V, which is why GM's battery energy control module treats a channel C reading of 4.8 V or more for 1.4 s within a 2 s window as a sensing fault and stores P0B48, Type A, one trip. On the 2012 two-mode full-size hybrids the threshold is scaled to a nickel-metal hydride block: block 3 above 23 V in 15 of 20 samples, Type B, two trips. Because the controller cannot trust the reading, it usually narrows the allowed charge and discharge power to protect the cells. For the driver this means less electric assist and possibly no plug-in charging. A cell that is really overcharged triggers separate cell voltage codes, not this one.
P0B48 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.3 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B48
- MIL and hybrid or EV system warning
- Reduced charge and discharge power
- Plug-in charging refused
Common causes of P0B48
- Most likelyChannel C sense line touching a tap of higher potential
- PossibleFailed measuring input or reference in the monitoring electronics
- Less likelyMonitoring software fault, check for controller updates
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 cWiring harnessBms
What each part of P0B48 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. |
| 48 | The exact fault in that area. |
What to do next
- Note P0B48 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 P0B48
What does P0B48 mean?
P0B48 means "Hybrid/EV Battery Voltage Sense C Circuit High". No healthy lithium-ion cell reaches 4.8 V, which is why GM's battery energy control module treats a channel C reading of 4.8 V or more for 1.4 s within a 2 s window as a sensing fault and stores P0B48, Type A, one trip. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B48?
Drive gently and only to a workshop. With P0B48 the car can go into limp mode (reduced power) to protect itself.
Will P0B48 fail an emissions test?
Yes, it can. P0B48 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 P0B48 to fix?
Difficulty: workshop only. A typical repair takes 0.3 to 6 hours of work. This is a job for a workshop.
Will P0B48 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.