Channel I is the ninth sense input of the battery monitoring chain, and P0B63 reports that its circuit is open. GM shows how differently this can be detected. The BAS Plus mild hybrid (table 13OBDG05C) watches the voltage of line N and its neighbour N-1: if both drop under 1.4 V and change by more than 0.5 V within 200 ms, 7 of 10 samples set the code, Type B. The newer battery energy control module of the 2019 tables relies on neighbouring cells drifting 1.3 V apart, a balancing test below 36 mV or a splice voltage, all within 0.6 s, Type A. Ford lists P0B63 among the open-line codes behind a no-start on the 2019-2020 Fusion plug-in hybrid and replaces the traction battery.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- Vehicle will not start or enter ready mode
- Service hybrid or EV system warning
- Electric mode unavailable
Most likely causes
- Broken channel I sense wire, crimp or cell tap
- Internal traction battery fault, pack replacement (Ford Fusion PHEV)
- Corroded or loose connector at the cell monitoring board
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0B63 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- B: Subsystem depends on the code range
- 63: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0B63?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0B63?
The most common causes are: broken channel I sense wire, crimp or cell tap; internal traction battery fault, pack replacement (Ford Fusion PHEV); corroded or loose connector at the cell monitoring board.
Related codes
- P0B64Hybrid/EV Battery Voltage Sense I Circuit Range/Performance
- P0B65Hybrid/EV Battery Voltage Sense I Circuit Low
- P0B66Hybrid/EV Battery Voltage Sense I Circuit High
- P0B67Hybrid/EV Battery Voltage Sense I Circuit Intermittent/Erratic
- P0B5EHybrid/EV Battery Voltage Sense H Circuit
- P0B68Hybrid/EV Battery Voltage Sense J Circuit
Sources
- gsi.ext.gm.com: 13OBDG05C Hybrid Diagnostics
- gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
- static.nhtsa.gov: MC 10232489 0001
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.