Powertrain, generic · Hybrid propulsion

P0B86 Hybrid/EV Battery Voltage Sense P Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B86 belongs to channel P, the sixteenth sense lead, and indicates that this lead has lost its connection to the cell. Comparing GM's tables shows how the timing evolved: the 2016 Volt battery controller decides within 0.6 s, the 2019 version waits 0.8 s in a 1.6 s window; both use the 1.3 V adjacent-cell, 36 mV balancing gate and splice criteria and are Type A. GM's 2016 program with a separate sense module measures the sense line resistance instead, failing above 30.00 in 7 of 9 samples. On the BAS Plus mild hybrid the code is Type B after 7 of 10 samples showing lines N and N-1 below 1.4 V with a step over 0.5 V. Ford's public bulletins do not list P0B86. The pack usually has to come out for repair.

Likely causes

Sense lead P open at the cell tap or connector
Excessive resistance in the sense line (corrosion, loose screw)
Defective input of the sense module

Symptoms

  • MIL and hybrid system fault message
  • Vehicle runs only on the engine or with reduced power

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–6,500
Time1–10 h

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

Parts involved

hv battery voltage sense pwiring harnessbms

Related codes

P0B87P0B88P0B89P0B8AP0B81P0B8B

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.