Powertrain, generic · Hybrid propulsion

P0B87 Hybrid/EV Battery Voltage Sense P Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B87 says channel P is delivering numbers that do not fit the rest of the battery. On GM's BAS Plus mild hybrid the cell under test must move at least 50 percent as far as the average cell voltage; if not, 20 failures in 40 samples set the code as Type B, i.e. MIL after two trips. GM's 2019 lithium-ion processor is stricter in its rating, Type A after 35 of 40 samples, and looks for a value that stays flat by less than 0.005 V while the average moves more than 0.022 V. The 2012 two-mode trucks check NiMH block 16, together with block 17, against the pack voltage with a 70 V window, 160 of 170 samples, Type B. Since wiring faults have their own codes (P0B86, P0B88, P0B89), this one points towards measuring electronics or software.

Likely causes

Measuring electronics for channel P out of tolerance
Software or calibration of the battery controller
NiMH block 16 or 17 out of balance with the pack

Symptoms

  • MIL after two trips on Type B systems
  • Engine start-stop or electric assist less frequent

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–5,000
Time0.5–6 h

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

Parts involved

hv battery voltage sense pwiring harnessbms

Related codes

P0B86P0B88P0B89P0B8AP0B82P0B8C

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