Powertrain, generic · Hybrid propulsion

P0B71 Hybrid/EV Battery Voltage Sense K Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B71 belongs to the unsteady fault type: the channel K reading flickers or drops out momentarily without staying beyond a fixed limit. No manufacturer documents this code publicly. Neither GM's hybrid tables from 2011 to 2019 nor the Ford and Chrysler bulletins on cell sense codes mention it, although they cover the open, plausibility, low and high codes of neighbouring channels. Its basis is the CARB requirement to monitor battery voltage sensors of the energy storage system as input components. In a workshop the approach would be a wiggle test on the module harness while watching cell voltage K live, plus a check of the connector terminals for fretting corrosion.

Likely causes

Fretting corrosion on channel K connector terminals
Sense harness under strain losing contact with movement

Symptoms

  • Warning that comes and goes
  • Occasional short loss of electric power

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–5,000
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

P0B6DP0B6EP0B6FP0B70P0B6CP0B76

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