Powertrain, generic · Hybrid propulsion

P0AC2 Hybrid/EV Battery Pack Current Sensor A Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

With P0AC2 the current sensor output sits above its valid window, which after conversion would mean an implausibly large current in the opposite direction to P0AC1. GM's 2016 and 2019 hybrid tables set it when the Hall-effect sensor reads above 274.6 A in 8 of 10 samples taken every 25 ms, again as Type A with immediate MIL. The 2013 table for an earlier pack uses an output above 4.65 V, roughly 215 A, with 7 of 10 samples and Type B. A signal shorted to the 5 V supply or an open sensor ground are common reasons. Because the controller can no longer count charge, it caps battery power; the low limit is P0AC1 and implausible offsets are P0AC0.

Likely causes

Sensor ground open
Signal wire shorted to the 5 V supply or another voltage
Hall current sensor failed internally

Symptoms

  • Hybrid system or check engine warning on
  • Battery power limited, engine runs more often

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€200–1,500
Time1–5 h

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

Parts involved

hv battery pack current sensor awiring harnessbms

Related codes

P0AC1P0AC0P0ABFP0AC3

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