Powertrain, generic · Hybrid propulsion

P0B68 Hybrid/EV Battery Voltage Sense J Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

For owners of a 2019 or 2020 Ford Fusion plug-in hybrid, P0B68 is best known from bulletin 23-2039: the car will not start, the battery energy control module stores one or more open sense line codes from P0B3B to P0B7C, and the prescribed repair is a complete high-voltage traction battery. Technically the code says that the tenth measuring channel, J, has lost its connection to the cells. GM describes the test in detail for its lithium-ion packs: within 0.6 s it looks for adjacent cells 1.3 V apart, a cell under 36 mV while being balanced, or splice voltages above 0.1 V or 0.5 V, and sets P0B68 as Type A. GM's BAS Plus mild hybrid uses a 1.4 V and 0.5 V rate-of-change test, Type B.

Likely causes

Internal traction battery failure, pack replacement (Ford Fusion PHEV 2019-2020)
Open sense wire or cell tap on channel J
Bad bus bar or splice connection near channel J

Symptoms

  • No start, vehicle does not become ready
  • Hybrid system warning on the cluster
  • Plug-in charging unavailable

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–8,000
Time1–8 h

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

Parts involved

hv battery voltage sense jwiring harnessbms

Related codes

P0B69P0B6AP0B6BP0B6CP0B63P0B6D

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