P227D code meaning
Barometric Pressure Sensor C Circuit High
Powertrain system Generic code P22xx codes Check engine light
What P227D means
P227D is the high-voltage counterpart of P227C. On GM's 2018 diesel the sensor C input has a pull-up, so both a short to the supply and a broken signal wire push it above 90.2 % of 5 V (about 115.4 kPa); after 320 failures in 400 samples it is a Type B fault. The supercharged LT4 uses 90 % (115 kPa) and attributes the code only to a short to power, here as Type A with the MIL on the first trip, because its input reads an open line as low. GM's 2023-2024 twin-throttle engine flags a reading above 115 kPa held for 2 s over two trips. Since the atmosphere cannot produce such a value at the sensor positions concerned, the ECM switches to a substitute, and corrections for altitude or boost become less exact.
P227D 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 P227D
- MIL on
- Little change in driving; possibly reduced boost or poorer altitude compensation
Common causes of P227D
- Most likelySignal wire of sensor C shorted to 5 V or battery voltage
- PossibleBroken signal wire or sensor ground on inputs with pull-up
- Less likelySensor C 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 P227D 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). |
| 7D | The exact fault in that area. |
What to do next
- Note P227D 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 P227D
What does P227D mean?
P227D means "Barometric Pressure Sensor C Circuit High". P227D is the high-voltage counterpart of P227C. It is a generic code, so it means the same on every make.
Is it safe to drive with P227D?
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 P227D fail an emissions test?
Yes, it can. P227D 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 P227D 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 P227D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.