P222C code meaning
Barometric Pressure Sensor B Circuit Low
Powertrain system Generic code P22xx codes Check engine light
What P222C means
P222C flags a sensor B voltage that has dropped too low, as with a signal wire touching ground. GM's 2018 tables for the 3.0 L LGW set the code below 40 % of the 5 V range, equal to about 50.9 kPa, counted in 320 of 400 readings taken every 12.5 ms; it is a Type B fault with the MIL after two trips. GM's 2023-2024 tables for a twin-throttle engine use the pressure value itself: below 50 kPa for 2 s. In GM software the fault bundle for ambient pressure sensor 2 covers exactly P222C and P222D, which tells which sensor letter B refers to there. Compared with sensor A (P2228), the circuit is separate, so sensor A keeps working. P222D is the high-voltage counterpart, P222B the plausibility check.
P222C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P222C
- Check engine light
- Scan tool shows a very low reading for the second barometric sensor
Common causes of P222C
- Most likelySignal wire of sensor B shorted to ground
- Possible5 V reference to sensor B open or shorted
- Less likelySensor B internally defective
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Barometric pressure sensorSensor wiring
What each part of P222C means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| 2C | The exact fault in that area. |
What to do next
- Note P222C 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 P222C
What does P222C mean?
P222C means "Barometric Pressure Sensor B Circuit Low". P222C flags a sensor B voltage that has dropped too low, as with a signal wire touching ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P222C?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P222C fail an emissions test?
Yes, it can. P222C is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P222C to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P222C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.