P0BA5: Hybrid/EV Battery Voltage Sense V Circuit Range/Performance

P0BA5 describes a sense V value that stays within limits but fails a rationality check against the other cells. GM's 16OBDG02 programme demands a trend of at least 0.002 V in the same direction as the average whenever that average moves more than 0.022 V, with 35 failures in 40 evaluations giving Type A. The 2019 hybrid processor works the same way with 0.005 V. For the 2016 model year GM lists two variants: the Volt with a 7 s in 8 s window and the ELR with 0.006 V of average movement and 20 of 40 samples at 200 ms. GM's eAssist expects half the average movement, Type B. Since the test is skipped while circuit, low or high faults are active, P0BA5 alone points to the measurement rather than an open lead.

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

MIL, little change in driving
Reduced regeneration or assist possible

Most likely causes

Channel V reading stuck while other cells move
Battery controller firmware needing reprogramming
Aged cell V responding differently to load

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
Compare the reading with other engine data while varying the engine speed.
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 P0BA5 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
B: Subsystem depends on the code range
A5: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0BA5?

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 P0BA5?

The most common causes are: channel V reading stuck while other cells move; battery controller firmware needing reprogramming; aged cell V responding differently to load.

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.