Powertrain, generic · Hybrid propulsion

P0B6F Hybrid/EV Battery Voltage Sense K Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

GM's BAS Plus mild hybrid, the eAssist system in table 13OBDG05C, gives P0B6F a simple rule: if the cell sense line for channel K measures below 1.4 V in 7 of 10 samples at 200 ms while the 12 V supply is above 8.8 V, the code is stored as Type B, two trips. Since a lithium-ion cell in use never falls that low, the value must come from a short or a failed input. GM's later battery energy control modules work with 0.2 V and a 1.4 s window, Type A, and the 2012 two-mode trucks with nickel-metal hydride blocks 11 and 12, both under 2 V. The driver typically sees a hybrid warning and loses electric assist; the engine takes over more of the work.

Likely causes

Channel K sense line shorted to ground or a lower tap

Failed measuring input in the battery interface module

Blown protective element in the sense line

Symptoms

Hybrid warning and MIL after the second trip
Auto stop and electric assist disabled

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€100–5,000

Time1–8 h

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

Parts involved

hv battery voltage sense kwiring harnessbms

Related codes

P0B6D P0B6E P0B70 P0B71 P0B6A P0B74

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