C057D code meaning
Brake Booster Temperature Sensor Circuit B Intermittent/Erratic
What C057D means
C057D is meant for a temperature B signal that drops out or jumps for brief moments instead of failing for good – a loose connector pin, a cracked solder joint or a wire breaking under vibration are the classic reasons. No manufacturer publishes a threshold for it. GM's monitors for this channel require several consecutive out-of-range samples (two or five) before storing C0579 or C057A, which filters single spikes; a separate code for unsteady behaviour is not listed in GM's public tables. Thermistor suppliers name mechanical stress, moisture and solder damage as frequent sources of unstable readings. The fault tends to come and go with temperature or road shocks and may return after clearing; while the signal is unreliable the booster can limit assist.
C057D at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of C057D
- Brake warning that appears and disappears
- Temperature B jumping on the scan tool
- Code returns some time after clearing
Common causes of C057D
- Most likelyLoose or fretting pin in the booster connector
- PossibleCracked solder joint of the thermistor on the circuit board
- PossibleMoisture ingress causing leakage currents at the sensor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake booster temp sensor bElectric brake booster
What each part of C057D means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7D | The exact fault in that area. |
What to do next
- Note C057D 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 C057D
What does C057D mean?
C057D means "Brake Booster Temperature Sensor Circuit B Intermittent/Erratic". C057D is meant for a temperature B signal that drops out or jumps for brief moments instead of failing for good – a loose connector pin, a cracked solder joint or a wire breaking under vibration are the classic reasons. It is a generic code, so it means the same on every make.
Is it safe to drive with C057D?
Drive gently and only to a workshop. With C057D the car can go into limp mode (reduced power) to protect itself.
Will C057D fail an emissions test?
C057D 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 C057D to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will C057D 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.