Powertrain, generic · Hybrid propulsion

P0ACB Hybrid/EV Battery Temperature Sensor C Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

With P0ACB the controller judges battery temperature sensor C implausible: its value deviates too far from what the other pack sensors report. GM applies the same limits as for sensors A and B. In the 2016 and 2019 tables the threshold is more than 25 °C away from the average of the other sensors in 50 of 67 samples; the 2011 and 2013 two-mode tables use more than 15 °C in 90 of 100; the 2013 table 13OBDG05C uses 8.55 °C after a soak of more than 6 hours. All are Type B, two trips. The Volt bulletin 18-NA-342 includes P0ACB among codes corrected by software. Without a bulletin, compare all sensors after an overnight soak to see whether only sensor C stands out.

Likely causes

Sensor C drifted from its characteristic
Controller software flags the sensor falsely (GM Volt bulletin 18-NA-342)
Corroded terminal adding resistance
Real temperature difference in the module monitored by sensor C

Symptoms

  • Check engine or hybrid warning light
  • Sensor C reads clearly off the others after a long soak
  • Possibly reduced charge and drive power

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 cwiring harnessbms

Related codes

P0ACAP0ACCP0ACDP0ACEP0AC6P0AE9

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