Powertrain, generic · Hybrid propulsion

P0BA4 Hybrid/EV Battery Voltage Sense V Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0BA4 reports an open or poorly connected sense V lead, the twenty-second channel and the last before W begins at P0BA9. GM's 2019 battery energy control module recognises it through seven cases, including 1.3 V between neighbouring cells, less than 36 mV with the balancing gate on and splice voltages above 0.1 or 0.5 V, with 0.8 s of failure in 1.6 s, Type A. The 2011 Volt already listed P0BA4 among its open sense line codes. In GM's 16OBDG02 programme a measured line resistance above 30.00 in 7 of 9 samples triggers it, in the eAssist mild hybrid low readings on lines N and N-1 together with a 0.5 V jump, Type B, gated by P1B38. Without a good sense lead the pack cannot balance or protect that cell.

Likely causes

Broken or unplugged sense lead V
High-resistance splice or busbar joint on channel V
Cell monitoring board fault on channel V

Symptoms

  • MIL and hybrid or EV system warning
  • Vehicle may not become ready to drive
  • Charging blocked

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 vwiring harnessbms

Related codes

P0BA5P0BA6P0BA7P0BA8P0B9FP0BA9

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