C059B code meaning
Brake Pressure Sensor B Missing Calibration
Chassis system Generic code C05xx codes Check engine light
What C059B means
The brake module cannot confirm that pressure sensor B has been calibrated and that its sensitivity is right. GM uses C059B in the brake controller of its 2016 and 2019 hybrid tables for the rear-left wheel pressure sensor: during a test pulse the sensor response must stay between 90 % and 110 %, checked only after at least one completed offset learn, with low master cylinder pressure and no ABS, traction or stability intervention. Type A, MIL after one trip; to confirm a fix, drive above about 6 mph for a minute without braking. In those same tables the rear-left sensor's circuit faults use C0575–C0578. A Bosch patent likewise treats a failed test pulse as a sensitivity fault with ABS and ESC lamps on. Ford checks sensor data by checksum and ID, but only for sensor A (C0560).
C059B at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of C059B
- ABS and stability control warning lamps on, MIL possible
- Regenerative braking blending or ESC functions restricted
Common causes of C059B
- Most likelyCalibration or offset learn not completed after module or hydraulic unit replacement
- PossiblePressure sensor responding outside the allowed test-pulse window
- Less likelyBrake control module storing or evaluating calibration data incorrectly
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake pressure sensor bBrake control module
What each part of C059B means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9B | The exact fault in that area. |
What to do next
- Note C059B 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 C059B
What does C059B mean?
C059B means "Brake Pressure Sensor B Missing Calibration". The brake module cannot confirm that pressure sensor B has been calibrated and that its sensitivity is right. It is a generic code, so it means the same on every make.
Is it safe to drive with C059B?
Drive gently and only to a workshop. With C059B the car can go into limp mode (reduced power) to protect itself.
Will C059B fail an emissions test?
C059B 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 C059B to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will C059B clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.