P0B48Hybrid/EV Battery Voltage Sense C Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- MIL and hybrid or EV system warning
- Reduced charge and discharge power
- Plug-in charging refused
- Likely causes
- LikelyChannel C sense line touching a tap of higher potential
- PossibleFailed measuring input or reference in the monitoring electronics
- RareMonitoring software fault, check for controller updates
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €50 – €5,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.