Powertrain, generic · Hybrid propulsion

P0B5A Hybrid/EV Battery Voltage Sense G Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B5A asks whether cell channel G behaves like a real cell. GM answers that question in three ways across its programmes. The 2019 hybrid tables expect channel G to trend with the average cell voltage and set the code after 35 frozen samples out of 40, Type A. The 2016 Chevrolet Volt uses a 7 of 8 second window, the Cadillac ELR 20 of 40 samples at 200 ms. The 2012 two-mode trucks compare block 7, multiplied by 20, with the pack voltage and fail it beyond 70 V in 160 of 170 samples, Type B. The Chrysler Pacifica bulletin stops at channel 6, so no other maker is documented for this code. A frozen or drifting measurement input is the most common cause.

Likely causes

Channel G measuring input frozen or drifting
Block 7 reading out of line with pack voltage (GM two-mode)
Monitoring software issue, check for updates

Symptoms

  • MIL without obvious drivability change
  • Limited hybrid assist

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€50–6,000
Time0.2–8 h

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

Parts involved

hv battery voltage sense gwiring harnessbms

Related codes

P0B59P0B5BP0B5CP0B5DP0B55P0B5F

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