C055E: Brake Hydraulic Circuit A Leak
Brake Hydraulic Circuit A Leak: a leak has been detected in this brake-hydraulic circuit, which reduces braking pressure. Safety-critical.
What C055E means
C055E is a generic OBD-II chassis code in the ABS & brakes group. In plain English: the computer found an electrical fault in that circuit: an open, short or bad connection, or a failed component.
- Check engine light
- Usually on
- Emissions-related
- No
- Limp mode possible
- Yes
- Drive cycle to clear
- Not required
Get it fixed
Post this code once and get quotes from local mechanics. Free to post.
Makes the repair and parts links below specific to your car. Kept in this browser only.
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
- 01Brake fluid leak in circuit AMost likely
Can I drive with C055E?
Not recommended beyond getting it to a shop.
This fault can put the vehicle in limp mode with reduced power, which can make merging and passing unsafe. Have it diagnosed as soon as possible.
Why we rate it urgent
- Can put the vehicle in limp mode (reduced power)
- Turns on the check engine light
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose C055E
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just C055E. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Check for related codes first
Look for C055D, C05B0, C05B1. Related codes often share a cause; a circuit or sensor code usually needs fixing before a performance code like this one.
- 3
Test the circuit
Inspect the wiring and connector at the brake circuit a for damage, corrosion or chafing. With a multimeter, check supply voltage, ground and signal against the specifications in the service manual for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Brake fluid leak in circuit A. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
C055E repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Hard
- Good DIY job?
- Usually a shop job
Involved testing or major parts. Most owners use a shop.
Parts and systems involved
- Brake circuit A
C055E FAQ
What does C055E mean?
C055E means “Brake Hydraulic Circuit A Leak”. Brake Hydraulic Circuit A Leak: a leak has been detected in this brake-hydraulic circuit, which reduces braking pressure. Safety-critical.
Is C055E serious? Can I keep driving?
We rate C055E as urgent severity. Not recommended beyond getting it to a shop. This fault can put the vehicle in limp mode with reduced power, which can make merging and passing unsafe. Have it diagnosed as soon as possible.
What causes C055E?
The most common causes, from most to least likely: Brake fluid leak in circuit A. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix C055E?
Typical labor is about $125–$750 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix C055E myself?
DIY difficulty is hard. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.
Will C055E clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.