C05C1 code meaning
Brake Pedal Position Sensor B Not Learned
What C05C1 means
Set when the second, redundant channel B of the brake pedal position sensor lacks a stored zero point. Many electric and hybrid brake pedals read travel twice so that one channel can cross-check the other; Bosch builds such pedal travel sensors with a magnetic field sensor and two redundant outputs. Without a learned rest value for B, that cross-check is lost even when channel A is fine. No manufacturer publishes C05C1. GM handles the comparable fault as C0277-4B and simply recalibrates, and Hitachi only accepts a new zero if the complete learn run finished without pedal input. After fitting a new pedal sensor or control unit, run the learn with the pedal fully released. C05C0 is the twin for channel A, C061A the offset-limit fault.
C05C1 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.3 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C05C1
- Brake warning lamp or service message
- Reduced redundancy, some assist or regeneration functions disabled
Common causes of C05C1
- Most likelyChannel B not learned after a repair or software update
- PossibleLearn conditions not met (pedal pressed, vehicle rolling)
- PossibleChannel B of the pedal sensor faulty or out of tolerance
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake pedal sensor bBrake control module
What each part of C05C1 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| C1 | The exact fault in that area. |
What to do next
- Note C05C1 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 C05C1
What does C05C1 mean?
C05C1 means "Brake Pedal Position Sensor B Not Learned". Set when the second, redundant channel B of the brake pedal position sensor lacks a stored zero point. It is a generic code, so it means the same on every make.
Is it safe to drive with C05C1?
Drive gently and only to a workshop. With C05C1 the car can go into limp mode (reduced power) to protect itself.
Will C05C1 fail an emissions test?
C05C1 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 C05C1 to fix?
Difficulty: medium. A typical repair takes 0.3 to 1.5 hours of work. This is a job for a workshop.
Will C05C1 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.