What Is the P0556 Code?
Symptoms
Causes
Seriousness
Can I Still Drive?
Diagnose
Difficulty of Inspecting
Get Additional Help
The definition of code P0556 is “Brake Booster Pressure Sensor Circuit Range/Performance.” This code indicates that your vehicle’s powertrain control module (PCM) or engine control module (ECM) has identified a malfunction that has in some way caused the brake booster pressure sensor circuit to operate out of its normal function. You can see this generic powertrain code in many OBD-II vehicles with a brake booster pressure sensor, which can include many makes and models.
More About the P0556 Code
Power brakes are an important part of vehicle braking in general. With power brakes, you don’t have to worry about stomping on the brakes as much; the power brake booster uses vacuum lines to add vacuum to the brake, adapting to various braking situations and ensuring effective brake pedal operation. It’s an important part of safely slowing down and stopping a vehicle. This code indicates that your power brake booster sensor circuit, which is responsible for transmitting this information to your PCM, is not providing normal readings.
Who Has the Lowest Price?
Some service centers will give you an online estimate to compare. Why drive around Town!?
What Are the Symptoms of a P0556 Code?
Most of the time, the common symptoms surrounding the P0556 powertrain diagnostic code are related to various lights on your dashboard. For example, you’ll probably see the check engine light turn on. You may also see the check brake light or other brake warning light illuminate on your dashboard if you have one of these. A general service engine soon light is also very common with this code. Finally, you may also see that it takes more effort for you to press the brake pedal.
What Are Some Causes of a P0556 Code?
The P0556 diagnostic trouble code is a generic code that can have a number of possible causes. Here are a few of the issues you might see with this code:
- Faulty or defective brake booster pressure sensor
- Issues with brake booster vacuum sensor
- Worn or damaged vacuum lines
- Vacuum leak
- Corroded or damaged connectors in the electrical system
- Damaged or faulty wiring
- Faulty or defective brake booster
- PCM issue or PCM programming error, although this is rare
To ensure the correct voltage input and accurate output voltage, the entire system needs to be functioning correctly. Any misstep can easily result in this pressure sensor trouble code.
How Serious Is the P0556 Code?
The P0556 code relates to your braking system, which means you should consider it fairly serious. While the brake booster error code very rarely causes severe braking concerns, it will definitely alter the way you’re able to brake in your vehicle, possibly also altering whether or not the brake lights come on. That can be a safety issue, but it can also lead to internal failure regarding other components of the engine as well. A faulty sensor can easily develop into a much more serious braking concern over time.
Can I Still Drive with a P0556 Code?
Most of the time, you’ll physically be able to drive with this code. It’s a small enough issue that it’s unlikely to result in any severely obvious defects. However, there are some systems within your vehicle that can be dangerous to drive, even with small issues, and the braking system is definitely one of them. While it may not impact vehicle speed and it may not even actually impact your ability to brake, booster pressure sensor trouble can quickly develop into a safety problem. You should avoid driving with this code active if possible, as it can be especially unsafe.
How Easy Is It to Diagnose a P0556 Code?
To diagnose the P0556 code, you need to be able to determine what’s causing the problem. Is it an actual faulty brake booster pressure sensor, or is there an issue with your wiring and general setup instead? You may need advanced equipment, like a digital multimeter, to diagnose the underlying problem. Running continuity tests and other important checks can also be necessary to diagnose the underlying problem. If you’re trying to avoid common mistakes, you’ll definitely want to talk to an expert.
How Difficult Is It to Inspect a P0556 Code?
To inspect the P0556 code, you’ll need a variety of resources and tools. Of course, you’ll probably need to perform a visual inspection, which can itself be tough for this system. On top of that, the troubleshooting process can be difficult. You may need to look at technical service bulletins, voltage requirements for your vehicle, and other technical references. While the serviceability level of this code is quite high, it’s often important that you get help from an expert to avoid needing a follow-up repair in just a few days, weeks, or months.
Need Additional Help with Your P0556 Code?
If you need extra help with the P0556 code, you’re definitely not alone. It’s extremely common to choose to let this one go with the experts. It’s complicated enough that many DIYers don’t want to try to handle it themselves. If you’re dealing with this problem, an expert can help you determine if the problem is a bad sensor, a faulty vacuum pump, or something else.
The first step should be to find an auto repair shop in your area. Because it’s not generally considered especially safe to drive with this code active, you want to find a shop as close to you as possible, which will allow you to get to the experts quickly.
Sometimes, this code can also come with other codes. The OBD-II database at KBB.com will allow you to look up all kinds of trouble codes on your code scanner so you can determine the possible causes related to them and get a better understanding of what fixes might be necessary.
P0556 Q&A
Common Error Codes
Browse All OBD-II Codes
Get Recall Alerts
All recalls are considered serious. Stay safe. Take care of any recalls ASAP. The good news? Recall repairs are free when performed at a local dealer.