Powertrain, generic · Hybrid propulsion

P0BC4 Hybrid/EV Battery Temperature Sensor E Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Sensor E is an NTC thermistor with a pull-up resistor, so its voltage falls as it gets hotter; a short to ground therefore looks like an extremely hot cell group. GM's 2016 table sets P0BC4 when the converted value exceeds 160 °C in 8 of 10 samples; the 2011 Volt table and GM's 2019 battery module table use above 87.5 °C for 1.4 s within 2 s; the eAssist mild hybrid flags a sense voltage under 0.3 V, about 90 °C, in 7 of 10 samples. All are Type B, two trips. Volt bulletin 18-NA-342 names it sensor 5 circuit low voltage. Its counterpart is P0BC5 (open circuit, reads very cold); a genuinely overheated pack is reported as P0A7E. Because the controller must assume heat, it cuts charge and discharge power and may run cooling at full speed.

Likely causes

Sensor E signal wire shorted to ground inside the pack
Internally shorted thermistor E
Moisture or contamination on the sensing board

Symptoms

  • MIL on after two trips
  • Implausibly high temperature for sensor E on the scan tool
  • Reduced power and battery fan or cooling at full speed

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–2,500
Time0.5–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery temp sensor ewiring harnessbms

Related codes

P0BC5P0BC3P0BC2P0A7EP0AEAP0C35

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