Powertrain, generic · Hybrid propulsion

P0BB3 Hybrid/EV Battery Voltage Sense Y Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0BB3 reports that the sense lead of channel Y, the twenty-fifth cell group, is no longer properly connected. GM's 16OBDG02 programme does not wait for odd voltages but calculates the resistance of the sense line and fails it above 30.00 in seven of nine samples, which is a one-trip Type A fault; the unit is missing in the table. The 2019 battery energy control module instead looks at the cell voltages themselves, for example 1.3 V between neighbours or a reading below 36 mV while that cell is being balanced, with 0.8 s of failure in 1.6 s. The eAssist mild hybrid sets it as a Type B fault when lines N and N-1 both read under 1.4 V and jump by more than 0.5 V. Low and high monitors for Y are blocked while P0BB3 is active.

Likely causes

Open circuit in sense lead Y
Corroded or loose terminal raising line resistance at Y
Cell monitoring slave board fault on input Y

Symptoms

  • MIL and high-voltage system warning
  • Vehicle may not start in electric mode
  • Charging aborted

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–7,000
Time1–10 h

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

Parts involved

hv battery voltage sense ywiring harnessbms

Related codes

P0BB4P0BB5P0BB6P0BB7P0BAEP0BB8

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