Powertrain, generic · Hybrid propulsion

P0BB5 Hybrid/EV Battery Voltage Sense Y Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0BB5 stands for a sense Y voltage below the plausible minimum. GM's 2016 Volt module and the 2019 battery energy control module both use 0.2 V or less for 1.4 s inside a 2 s window and flag it as Type A. Before testing, the 2019 module makes sure that no open sense line, no lost communication with the cell monitoring slave and no balancing or internal slave fault is active, and that the second protection self test is not running. The eAssist mild hybrid sets the code below 1.4 V in seven of ten samples, Type B. The likely culprits are a pinched sense wire touching a lower potential, a failed measuring channel or a cell that has really lost its charge. The driver sees a warning and reduced performance.

Likely causes

Pinched sense wire Y shorting to a lower potential
Failed measuring channel Y
Cell Y severely discharged

Symptoms

  • Hybrid or EV warning with MIL
  • Noticeably reduced power

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 ywiring harnessbms

Related codes

P0BB3P0BB4P0BB6P0BB7P0BB0P0BBA

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