PowertrainP1556

Serious

Severity: Serious - have it checked soon

Small leakage of vacuum degree of brake vacuum booster pump

27 brands affected · Description from Toyota data.

Key terms: Boost pressure: extra air pressure made by a turbo or supercharger · Powertrain: engine, transmission and emissions

Safety: This code relates to the braking system or brake assist. Braking may be affected.

1What it means in plain English

There is a small vacuum leak in the brake booster system, so brake assistance may be reduced.

2Common causes

Leaking brake vacuum hose or booster
Faulty vacuum sensor
Damaged wiring or connector
Worn booster seal
Failing vacuum pump

3Can I drive?

Serious · drive with care

Brakes may need more pedal effort than normal. Have it checked before driving further; if the pedal feels hard or stopping distances increase, stop safely and have the car recovered.

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 27

Brand	Code	Description	System
BAIC Motor	P1556	Brake Vacuum Power Pump Vacuum Degree Small Leak Brand	Powertrain
Mercedes-Benz	P1556	No description available	Powertrain
Chery	P1556	Charge Pressure Contr. Negative Deviation Brand	Powertrain
Daewoo	P1556	Charge Deviations Brand	Powertrain
DFFS	P1556	BECB system voltage fault Brand	Powertrain
DFFX	P1556	Brake vacuum booster pump vacuum leakage Brand	Powertrain
DFXK	P1556	Brake booster vacuum small leakage Brand	Powertrain
EOBD	P1556	Ladeafvigelser Brand	Powertrain
Geely	P1556	Charge Pressure Contr. Negative Deviation Brand	Powertrain
GM	P1556	Charge Deviations Brand	Powertrain
Great Wall	P1556	Charge Pressure Contr. Negative Deviation Brand	Powertrain
Holden	P1556	Brake Booster Pump Motor Brand	Powertrain
Honda	P1556	No description available	Powertrain
Land Rover	P1556	Injector circuit range/performance - cylinder 6 Brand	Powertrain
Maserati	P1556	No description available	Powertrain
Mitsubishi	P1556	No description available	Powertrain
Nissan	P1556	No description available	Powertrain
Opel	P1556	Charge Deviations Brand	Powertrain
Peugeot	P1556	No description available	Powertrain
Porsche	P1556	No description available	Powertrain
Proton	P1556	Charge Pressure Contr. Negative Deviation Brand	Powertrain
Saab	P1556	Charge Deviations Brand	Powertrain
Sprinter	P1556	No description available	Powertrain
Suzuki	P1556	BAT TMP SEN/CIRC Brand	Powertrain
SWM Motor	P1556	Brake vacuum booster pump vacuum leakage Brand	Powertrain
Toyota	P1556	Small leakage of vacuum degree of brake vacuum booster pump Brand	Powertrain
Volkswagen	P1556	Charge Pressure Control: Negative Deviation 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.

5Related codes

Browse Pxxx codes or P155xx codes.