P0AC2: Hybrid/EV Battery Pack Current Sensor A Circuit High

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.

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

Most likely causes

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

What to check, in order

Start with the simplest. You can tick off each step.

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
Leave any high-voltage measurements to a specialized repair shop

Good to know

It can trigger limp mode.
It affects emissions.

What each character of P0AC2 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
A: Hybrid or air and fuel
C2: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0AC2?

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 P0AC2?

The most common causes are: sensor ground open; signal wire shorted to the 5 V supply or another voltage; hall current sensor failed internally.

Related codes

Sources

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.