PowertrainP0AA2

Caution

Severity: Caution - get it checked when you can

Battery management system (BMS) voltage signal is invalid

26 brands affected · Description from Toyota data.

Key terms: Control module: a small computer that runs one part of the car · Powertrain: engine, transmission and emissions

1What it means in plain English

The engine or powertrain control system has stored a fault that does not have specific guidance in this database yet.

2Common causes

Sensor or actuator fault
Wiring or connector fault
Vacuum or intake leak
Fuel or ignition problem
Control module fault

3Can I drive?

Caution · drive with care

Have it diagnosed promptly. If the car runs and drives normally, drive gently to a workshop. If it runs badly, stalls, overheats, loses oil pressure, or a warning light is flashing or red, stop safely and get professional help. If the code concerns the brakes, brake vacuum or brake assist, do not drive until it is checked: a hard pedal or longer stopping distance means stop.

This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.

4Brand data 26

Brand	Code	Description	System
Ashok Leyland CV	P0AA2	No description available	Powertrain
BAIC Motor	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Mercedes-Benz	P0AA2	No description available	Powertrain
BYD	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Chery	P0AA2	Gear shift actuator sensor failure Brand	Powertrain
Daewoo	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
DFFS	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
DFFX	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
DFXK	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
EOBD	P0AA2	Hybrid/EV battery positive contactor circuit stuck open Brand	Powertrain
Ford	P0AA2	No description available	Powertrain
Geely	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
GM	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Great Wall	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Hafei	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Holden	P0AA2	Hybrid/EV Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Honda	P0AA2	No description available	Powertrain
Hyundai	P0AA2	No description available	Powertrain
Isuzu	P0AA2	No description available	Powertrain
Land Rover	P0AA2	No description available	Powertrain
Opel	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Peugeot	P0AA2	No description available	Powertrain
Saab	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
MG (SAIC)	P0AA2	Hybrid Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Suzuki	P0AA2	Hybrid/EV Battery Positive Contactor Circuit Stuck Open Brand	Powertrain
Toyota	P0AA2	Battery management system (BMS) voltage signal is invalid Brand	Powertrain

Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.

5Extended variant codes 3

These 7-character codes are manufacturer-specific variants of P0AA2 and may be reported by some scan tools.

Brand	Code	Description	System
Volkswagen	P0AA200	Hybrid/High-Voltage Battery Positive Contact Stuck in Open Position Brand	Powertrain
Mercedes-Benz	P0AA294	The contact 'Positive terminal' of contactor A in the high-voltage battery is jammed open. There is an unexpected instruction. Brand	Powertrain
Mercedes-Benz	P0AA29E	The contact 'Positive terminal' of contactor A in the high-voltage battery is jammed open. The switch is jammed open. Brand	Powertrain

6Related codes

Browse Pxxx codes or P0AAxx codes.