Powertrain, generic · Hybrid propulsion

P0B6A Hybrid/EV Battery Voltage Sense J Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

A reading of almost zero on channel J points to the measurement, not to the cell, and that is what P0B6A records. In GM's lithium-ion systems (2016 and 2019 tables) the battery energy control module sets it at 0.2 V or less for 1.4 s within 2 s, Type A. The interesting part is what it ignores: while a module communication loss, an open sense line code, a balancing fault or an internal module fault is active, P0B6A stays silent so that the root cause is stored first. The 2012 two-mode hybrids look at nickel-metal hydride block 10 together with block 11, both below 2 V in 15 of 20 samples, Type B. Expect reduced or no electric drive until the circuit is repaired.

Likely causes

Channel J lead chafed through and shorted to ground
Damaged measuring input on the monitoring board
Cell on channel J internally shorted

Symptoms

  • Electric drive limited or unavailable
  • MIL and battery warning message

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–6,000
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

P0B68P0B69P0B6BP0B6CP0B65P0B6F

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, law.cornell.edu.