C063B code meaning
Brake Pressure Sensor H Circuit Low
What C063B means
C063B says sensor H reads below its valid floor. Unlike C063C the problem is electrical, not a believable but wrong pressure. A Bosch workshop article on a Teves MK60 unit describes the integrated sensor: fed with 5 V, it stays below 1 V with the brakes off and climbs as pedal pressure builds, so the fault limit has to sit well under that rest level. GM's 2019 EBCM flags its circuit pressure sensor as shorted low when the main channel falls under 4.61 % of supply, or the reference channel under 4.85 %, for 100 ms. Where H sits is not published; in Toyota's eight-sensor design the candidates would be a wheel cylinder, the booster chamber or the pump output. Likely: signal shorted to ground, collapsed 5 V reference or a dead sensor.
C063B at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C063B
- ABS and ESC lamps on
- Brake assist and stability control not available
Common causes of C063B
- Most likelySignal conductor shorted to ground
- Possible5 V reference collapsed by a short in another sensor on the same feed
- PossibleSensor H without output due to an internal defect
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake pressure sensor hSensor wiring
What each part of C063B means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3B | The exact fault in that area. |
What to do next
- Note C063B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C063B
What does C063B mean?
C063B means "Brake Pressure Sensor H Circuit Low". C063B says sensor H reads below its valid floor. It is a generic code, so it means the same on every make.
Is it safe to drive with C063B?
Drive gently and only to a workshop. With C063B the car can go into limp mode (reduced power) to protect itself.
Will C063B fail an emissions test?
C063B is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C063B to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will C063B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.