C05CC code meaning
Brake Master Cylinder Piston Position Sensor A Circuit Range/Performance
Chassis system Generic code C05xx codes Check engine light
What C05CC means
Channel A (GM calls it PTS1) delivers a travel value that is electrically valid but physically wrong. GM's integrated controller with pedal simulator, the vacuum-free design ZF supplies, checks three things: travel above 38 mm (normal input piston travel is about 25 mm, about 36 mm without boost), a change faster than 700 mm/s, and a learned offset beyond 2.5 mm, each 100 ms, Type A. In the XT4 booster module the zero offset with pedal released may not exceed 0.9 mm while driving and accelerating; 23OBDG07 and 25OBDG03B allow +1.1/-1.5 mm. Causes range from a failed sensor to a bent sensor rod or wrong mounting. C05CF is the same check on channel B, C05D0 compares both channels.
C05CC at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C05CC
- Malfunction indicator lamp and brake warning
- Changed pedal feel or reduced assist
- Brake lights may react inconsistently
Common causes of C05CC
- Most likelySensor A offset drifted beyond the learn limit
- PossibleDamaged travel sensor rod or mounting
- PossibleIntermittent signal line producing jumps
- Less likelyPedal not fully returning (floor mat, return spring)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Master cylinder pos sensor aElectric brake booster
What each part of C05CC means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| CC | The exact fault in that area. |
What to do next
- Note C05CC 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 C05CC
What does C05CC mean?
C05CC means "Brake Master Cylinder Piston Position Sensor A Circuit Range/Performance". Channel A (GM calls it PTS1) delivers a travel value that is electrically valid but physically wrong. It is a generic code, so it means the same on every make.
Is it safe to drive with C05CC?
Drive gently and only to a workshop. With C05CC the car can go into limp mode (reduced power) to protect itself.
Will C05CC fail an emissions test?
C05CC 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 C05CC to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will C05CC clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.