Powertrain, generic · Hybrid propulsion

P0B6B Hybrid/EV Battery Voltage Sense J Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

On GM's 2012 two-mode hybrid trucks the battery is divided into 20 nickel-metal hydride blocks, and channel J is block 10. The battery pack control module samples it every 100 ms while the 12 V supply is between 9 and 18 V; if block 10 reports more than 23 V in 15 of 20 samples, P0B6B is stored as Type B, so the MIL comes on after the second trip. Lithium-ion GM packs check single cells instead and set the code at 4.8 V or more for 1.4 s within 2 s, Type A; the BAS Plus mild hybrid uses 4.65 V. Since these limits lie well above any real charge level, a wiring short to a higher tap or a faulty sense input is the expected finding, not an overcharged battery.

Likely causes

Channel J lead shorted to a higher block or cell tap
Faulty measuring input in the battery pack control module

Symptoms

  • MIL after the second drive (Type B systems)
  • Charging or regeneration restricted
  • Reduced electric power

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

P0B68P0B69P0B6AP0B6CP0B66P0B70

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