C0258 code meaning
Brake Booster Vacuum Sensor Circuit
What C0258 means
No public record of C0258 exists: the publicly available J2012 lists, the NHTSA bulletin index and the GM and Saab indexes all lack it. Only the sensor named in the title can be described. A booster vacuum sensor tells the control unit whether enough vacuum is stored for power-assisted braking; GM needs it on cylinder-deactivation engines, which return to all cylinders when vacuum gets low. GM patent US7076347 checks the sensor with the throttle almost closed: over one second the gap to manifold vacuum must shrink to near zero. GM patent US7467544 also catches a reading biased high or low. Electrical faults of such a sensor are normally stored as powertrain codes P0556 to P0559 rather than as a chassis code.
C0258 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0258
- Warning lamp or message about brake assistance
- Cylinder deactivation or engine stop-start inhibited on affected vehicles
Common causes of C0258
- PossibleOpen or shorted sensor supply, ground or signal wire
- PossibleFaulty or drifting vacuum sensor
- Less likelyLeaking vacuum hose, check valve or booster diaphragm
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake booster vacuum sensorVacuum hose
What each part of C0258 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 58 | The exact fault in that area. |
What to do next
- Note C0258 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 C0258
What does C0258 mean?
C0258 means "Brake Booster Vacuum Sensor Circuit". No public record of C0258 exists: the publicly available J2012 lists, the NHTSA bulletin index and the GM and Saab indexes all lack it. It is a generic code, so it means the same on every make.
Is it safe to drive with C0258?
C0258 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will C0258 fail an emissions test?
C0258 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 C0258 to fix?
Difficulty: medium. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will C0258 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.