Powertrain, generic · Hybrid propulsion

P0B98 Hybrid/EV Battery Voltage Sense S Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B98 marks a sense S value that is too high to be a cell voltage. The thresholds vary with the battery chemistry and controller: GM's 2016 Volt and 2019 battery controllers flag 4.8 V or more after 1.4 s in 2 s (Type A), the 16OBDG02 programme 4.90 V in 14 of 18 samples (Type A), and the eAssist mild hybrid more than 4.65 V in 7 of 10 samples with the 12 V supply above 8.8 V (Type B). On the 2012 two-mode trucks S is NiMH block 19 and its limit is 23 V, 15 of 20 samples, Type B. Like the low test, the high test waits until open sense line faults are ruled out. The fix is usually wiring or the monitoring board; a truly overcharged cell is rare but must be excluded.

Likely causes

Sense lead S shorted to a higher cell or busbar
Measuring chip reading channel S incorrectly
Real overvoltage of the cell or block on channel S

Symptoms

  • MIL and service hybrid system message
  • Charging and regeneration limited

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 swiring harnessbms

Related codes

P0B95P0B96P0B97P0B99P0B93P0B9D

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