Powertrain, generic · Hybrid propulsion

P0B57 Hybrid/EV Battery Voltage Sense F Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B57 stands for an implausibly high value on cell sense channel F, as opposed to P0B56 for an implausibly low one and P0B55 for a frozen value. GM uses fixed upper limits: 4.8 V or more for 1.4 s within 2 s in the battery energy control module of its lithium-ion systems (Type A, one trip), and above 23 V for block 6 in the 2012 two-mode trucks (15 of 20 samples, Type B, two trips). Both values lie clearly above what the cell or block can physically reach, so a real overcharge is not the explanation. Look for a sense lead in contact with a higher potential or for a measuring fault inside the module, and expect limited battery power and charging until then.

Likely causes

Channel F sense lead touching a higher potential
Measuring input or reference fault in the module

Symptoms

  • MIL and battery warning
  • Battery charging limited
  • Weaker acceleration in hybrid mode

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€50–5,000
Time0.3–6 h

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

Parts involved

hv battery voltage sense fwiring harnessbms

Related codes

P0B54P0B55P0B56P0B58P0B52P0B5C

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