Powertrain, generic · Hybrid propulsion

P0AFA Hybrid/EV Battery System Voltage Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P0AFA protects the traction battery from deep discharge: the pack voltage, or in some versions any cell voltage, has fallen below a temperature-dependent limit. GM's 2016 and 2019 tables set it after 320 of 400 samples (about 10 s) for the pack or 112 of 140 for a cell, Type A, and latch it so that only a technician command can clear it. GM bulletins name causes: degraded cell groups in 2011-15 Volt and ELR (19-NA-117), a blown fuse in the Bolt EV manual disconnect lever (18-NA-225), cell contamination in the 2015 Spark EV (17-NA-131) and repeated cranking that empties the Malibu Hybrid pack (PIC6229). A Ram eTorque parts notice names it for the 48 V power pack. Expect a no-start.

Likely causes

Degraded or self-discharging cell groups

Pack drained by repeated failed engine starts or long standing

Open high-voltage fuse or manual disconnect

Loose or high-resistance ground on 48 V systems

Symptoms

Vehicle does not start; restart blocked while the code is latched
Reduced or lost propulsion before the no-start
Plug-in charging not possible

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€200–9,000

Time1–10 h

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

Parts involved

hv batterybms

Related codes

P0AFB P0AF8 P0AF9 P0BBE P0ABC

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.