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P0556ModerateChassis

P0556: Brake Booster Pressure Sensor Circuit Range/Performance

8 vehicles · 5 makes · $300-$1,800 repair

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Most Reported On

2019-2023Chevrolet Silverado 15002015-2020Ford F-1502014-2018GMC Sierra 15002015-2018GMC Yukon2015-2018Chevrolet Suburban

P0556 is an OBD-II diagnostic trouble code meaning “Brake Booster Pressure Sensor Circuit Range/Performance.” The brake booster pressure sensor signal is present but out of the expected range or implausible relative to operating conditions. A range/performance fault. This code is most commonly reported on 2019-2023 Chevrolet Silverado 1500, 2015-2020 Ford F-150, and 2014-2018 GMC Sierra 1500, plus 5 other vehicles, with repair costs ranging from $300 to $1,800.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (8)
  • Related Codes
  • FAQ
  • Sources (9)

Makes

  • Cadillac1
  • Chevrolet4
  • Ford1
  • GMC3
  • Toyota1
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Common Causes

1Faulty brake booster pressure sensor
2Vacuum leak at the booster or hose
3Wiring resistance / poor connection
4Failing vacuum source / pump
5Faulty PCM input

Typical Repair Cost

$300 - $1,800

Based on 10 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.

Diagnostic Tools

This is a powertrain code, so a basic OBD-II reader can read it. These read P0556.

Reads P codes$20–$40

ANCEL AD310 Classic OBD-II Scanner

by ANCEL

A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.

  • ✓Read & clear engine (P) codes
  • ✓View freeze frame data
  • ✓I/M readiness status
  • ✓No batteries or app needed
Check Price on Amazon
Reads P codes$90–$120

BlueDriver Pro Bluetooth Scanner

by BlueDriver

Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.

  • ✓Enhanced diagnostics (ABS, SRS, transmission)
  • ✓Repair Reports with verified fixes
  • ✓Smog check readiness
  • ✓Free app (iOS & Android)
Check Price on Amazon
Reads P codes$180–$230

LAUNCH CRP123X V3.0 Elite OBD-II Scanner

by LAUNCH

Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

  • ✓Engine, transmission, ABS, SRS diagnostics
  • ✓Live data stream & graphing
  • ✓AutoVIN for vehicle identification
  • ✓Free lifetime updates via Wi-Fi
Check Price on Amazon
Reads P codes$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

by Autel

Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.

  • ✓All-system diagnostics (25+ modules)
  • ✓Bi-directional control & active tests
  • ✓Oil reset, EPB, BMS, TPMS, injector coding
  • ✓7-inch touchscreen with Android OS
Check Price on Amazon

What you can do yourself, and what needs a shop

Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:

  • •Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
  • •Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
  • •Airbag/SRS component work — a stored fault can deploy a live device.

If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.

As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.

Vehicles Affected (8)

Cadillac P0556 page →
EscaladeCritical

Escalade Power Brake Assist Can Fade With Vacuum Pump Output (Recall 19V645000)

2015-2017
Chevrolet P0556 page →
Silverado 1500Critical

Brake Booster/Assist Malfunction (T1)

2019-2023$500-$1,8001,100 owner reports
SuburbanCritical

Suburban Brake Assist Loss From Decreasing Vacuum Pump Output - Recall 19V645000

2015-2018
EquinoxCritical

Engine-driven brake vacuum pump failure causing sudden hard brake pedal

2018-2022$400-$1,200
Silverado 1500Critical

Brake vacuum pump degradation reducing power brake assist (NHTSA recall 19V645)

2014-2018$0-$400
Ford P0556 page →
F-150Critical

Brake Vacuum Pump Failure (EcoBoost)

2015-2020$300-$800680 owner reports
GMC P0556 page →
Sierra 1500Critical

NHTSA Recall 19V645000: Declining Vacuum Pump Output Reduces Power Brake Assist

2014-2018
YukonCritical

GM Recall 19V645000: EBCM Reprogram for Declining Vacuum Brake Assist

2015-2018
YukonCritical

Brake Vacuum Pump Failure Causing Hard Brake Pedal

2015-2018
Toyota P0556 page →
CamryCritical

Certain 2018-2019 Camry Vacuum-Pump Brake-Assist Recall - 21V890

2018-2019$0-$0

Related Codes (8)

P0550Power Steering Pressure Sensor/Switch Circuit MalfunctionP0551Power Steering Pressure Sensor/Switch Circuit Range/PerformanceP0552Power Steering Pressure Sensor/Switch Circuit Low InputP0553Power Steering Pressure Sensor/Switch Circuit High InputC0031Left Front Wheel Speed Sensor CircuitC0034Right Front Wheel Speed Sensor CircuitC0036Left Front Wheel Speed Sensor CircuitC0037Left Rear Wheel Speed Sensor Circuit

FAQ

What does P0556 mean?

P0556 stands for "Brake Booster Pressure Sensor Circuit Range/Performance." The brake booster pressure sensor signal is present but out of the expected range or implausible relative to operating conditions. A range/performance fault.

What are the most common causes of P0556?

The most common causes of P0556 are: Faulty brake booster pressure sensor, Vacuum leak at the booster or hose, Wiring resistance / poor connection, Failing vacuum source / pump, Faulty PCM input. The specific cause varies by vehicle.

How much does it cost to fix P0556?

Repair costs for P0556 range from $300 to $1,800, depending on the vehicle and root cause.

Which vehicles are affected by P0556?

Au7o has documented P0556 across 8 vehicle models from 5 manufacturers: Cadillac, Chevrolet, Ford, GMC, Toyota.

Sources (9)

  • RecallNHTSA Recall 20V-055 / GM N192268091 - Brake System Malfunction Warning
  • NHTSANHTSA Manufacturer Communications Data Corpus
  • RecallNHTSA Recall 19V645000 - GMC Sierra Vacuum Pump Brake Assist Loss (GM N192268490)
  • RecallNHTSA Recall 18V576 - Rear Caliper Pistons Can Reduce Braking Performance
  • RecallNHTSA Campaign 19V645 - Decreasing Vacuum Brake-Assist Recall
  • RecallNHTSA Recall 21V890 Part 573 Report: Vacuum-Pump Brake Assist
  • RecallToyota 21TA09 Camry Owner Remedy Notice
  • NHTSANHTSA VIN Recall Lookup
  • RecallNHTSA Recall 19V-645 - Reduced Vacuum Brake Assist
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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