Battery temperature sensor E is the fifth thermistor in the high-voltage pack; GM's Chevrolet Volt bulletin 18-NA-342 lists the E codes as temperature sensor 5 of nine. P0BC2 is the general circuit code, used when the controller detects an electrical fault without classing it as low, high or erratic. GM's hybrid tables report only the specific siblings P0BC3 to P0BC6. NHTSA's summary of an Audi pending service solution for 2027 Q6 and A6 e-tron models names P0BC2 with a failure type byte among implausible temperature sensor errors. CARB requires battery temperature sensors to be monitored for circuit faults. With one value missing the controller limits charge and discharge power. The sensor sits inside the pack, so checks call for high-voltage safety procedures.
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
- Hybrid or EV system warning and MIL
- Reduced power or charging rate
- Battery cooling running more than usual
Most likely causes
- Loose or corroded connector of sensor E at the sensing board
- Failed thermistor E
- Faulty input on the battery sensing board or module
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 P0BC2 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- B: Subsystem depends on the code range
- C2: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0BC2?
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 P0BC2?
The most common causes are: loose or corroded connector of sensor E at the sensing board; failed thermistor E; faulty input on the battery sensing board or module.
Related codes
- P0BC3Hybrid/EV Battery Temperature Sensor E Circuit Range/Performance
- P0BC4Hybrid/EV Battery Temperature Sensor E Circuit Low
- P0BC5Hybrid/EV Battery Temperature Sensor E Circuit High
- P0BC6Hybrid/EV Battery Temperature Sensor E Circuit Intermittent/Erratic
- P0AE8Hybrid/EV Battery Temperature Sensor D Circuit
- P0C33Hybrid/EV Battery Temperature Sensor F Circuit
- P0C71Hybrid/EV Battery Temperature Sensor D/E Correlation
- P0C72Hybrid/EV Battery Temperature Sensor E/F Correlation
Sources
- law.cornell.edu: 13 CCR 1968.2
- static.nhtsa.gov: MC 10155116 9999
- gsi.ext.gm.com: 16OBDG02 Hybrid Diagnostics
- static.nhtsa.gov: MC 11035841 0001
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.