Powertrain, generic · Hybrid propulsion

P0B64 Hybrid/EV Battery Voltage Sense I Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B64 is a rationality fault: channel I is connected and reads a believable number, yet it does not move with the other cells. GM's 2016 Chevrolet Volt compares the movement of each cell with the average; if channel I does not follow when the average moves by more than 0.022 V, 7 out of 8 seconds fail the check, Type A. The 2019 hybrid powertrain control processor 2 tables keep the idea but count samples, 35 failures out of 40 at 100 ms. On the 2012 two-mode trucks the same code belongs to nickel-metal hydride block 9, whose scaled value must stay within 70 V of the pack voltage. Because the input is alive but stuck or drifting, a software update or the monitoring board is a likelier fix than wiring.

Likely causes

Channel I measuring input frozen at a constant value
Battery controller software misjudging the channel
High-resistance cell tap damping the signal

Symptoms

  • MIL on, vehicle drives normally
  • Reduced hybrid assist or electric range

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€50–5,000
Time0.3–8 h

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

Parts involved

hv battery voltage sense iwiring harnessbms

Related codes

P0B63P0B65P0B66P0B67P0B5FP0B69

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