Powertrain, generic · Hybrid propulsion

P0B90 Hybrid/EV Battery Voltage Sense R Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B90 is stored when the battery controller concludes that the tap of sense R, the eighteenth cell channel, is open or too resistive. GM's 2019 battery energy control module runs seven cases for it: neighbouring cells 1.3 V or more apart, a reading under 36 mV while the balancing gate is on, or splice voltages above 0.1 V (0.5 V at a busbar splice). The fault has to be present for 0.8 s within a 1.6 s window and is Type A. The 2016 Volt and ELR use the same cases with a 0.6 s window. Oddly, GM's first-generation Volt tables of 2011 to 2015 contain no P0B90 at all, although they list the circuit codes of S to V. Range, low and high faults of R are P0B91 to P0B93.

Likely causes

Loose, corroded or broken tap of sense lead R
Excessive resistance at a splice or busbar joint feeding channel R
Faulty measuring or balancing input on the cell monitoring board

Symptoms

  • MIL with service hybrid or EV system warning
  • Reduced propulsion power or no ready mode
  • Charging interrupted or refused

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 rwiring harnessbms

Related codes

P0B91P0B92P0B93P0B94P0B8BP0B95

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