Powertrain, generic · Hybrid propulsion

P0B63 Hybrid/EV Battery Voltage Sense I Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

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

Symptoms

  • Vehicle will not start or enter ready mode
  • Service hybrid or EV system warning
  • Electric mode unavailable

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–8,000
Time0.5–8 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery voltage sense iwiring harnessbms

Related codes

P0B64P0B65P0B66P0B67P0B5EP0B68

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, law.cornell.edu.