Powertrain, generic · Hybrid propulsion

P0B65 Hybrid/EV Battery Voltage Sense I Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The 2012 GM two-mode hybrids show a detail worth knowing for P0B65: their battery pack control module only declares channel I, nickel-metal hydride block 9, too low when block 9 and its neighbour block 10 both read under 2 V, and only after 15 of 20 samples at 100 ms; the fault is Type B and needs two trips. A single weak block alone therefore does not set it. GM's lithium-ion controllers judge each cell on its own, setting P0B65 at 0.2 V or less held for 1.4 s within 2 s, Type A, as long as no open-line or communication fault has priority. The BAS Plus mild hybrid uses 1.4 V and 7 of 10 samples. In all cases the reading is too low to be a real cell.

Likely causes

Channel I sense lead shorted to ground or a lower tap
Connector fault affecting adjacent blocks 9 and 10 (two-mode)
Failed measuring input in the battery controller

Symptoms

  • Hybrid system warning and MIL
  • Engine runs more often, electric assist reduced
  • Limited power in limp mode

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 iwiring harnessbms

Related codes

P0B63P0B64P0B66P0B67P0B60P0B6A

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