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.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- MIL with service hybrid or EV system warning
- Reduced propulsion power or no ready mode
- Charging interrupted or refused
Most 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
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0B90 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- B: Subsystem depends on the code range
- 90: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0B90?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0B90?
The most common causes are: 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.
Related codes
- P0B91Hybrid/EV Battery Voltage Sense R Circuit Range/Performance
- P0B92Hybrid/EV Battery Voltage Sense R Circuit Low
- P0B93Hybrid/EV Battery Voltage Sense R Circuit High
- P0B94Hybrid/EV Battery Voltage Sense R Circuit Intermittent/Erratic
- P0B8BHybrid/EV Battery Voltage Sense Q Circuit
- P0B95Hybrid/EV Battery Voltage Sense S Circuit
Sources
- gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
- gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
- gsi.ext.gm.com: 11OBDG01 HYBRID Diagnostics
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.