The OBD2 code P012D is triggered when the engine control module detects a higher than expected signal from the turbocharger or supercharger inlet pressure sensor. This sensor monitors air pressure entering the engine, ensuring the right air-to-fuel ratio for performance. A high signal could mean a problem with the sensor, its wiring, or excessive air pressure, causing issues like stalling and reduced power.
P012D quick overview
| Meaning | P012D: Turbocharger/Supercharger Inlet Pressure Sensor Circuit High |
| Is it serious? | Yes, it can significantly affect engine performance and health if not addressed. |
| Possible causes | – Faulty turbocharger/supercharger inlet pressure sensor – Wiring or connector issues in the sensor circuit – Vacuum or pressure leaks in the intake system – Faulty ECM (less common) |
| How to diagnose? | Inspect the sensor and its wiring harness for visible damage or corrosion. Test the sensor connector for proper contact and corrosion. Check all ground connections related to the sensor circuit for integrity. Verify the condition of the air filter, as a severely restricted filter can impact pressure readings. Replace the sensor and repair any damaged wiring as needed. |
P012D Meaning
When you encounter a P012D code, it means the car’s computer has detected unusually high air pressure at the entrance to the turbocharger or supercharger, which can mess with the engine’s power output.
This might be because the sensor measuring this pressure is broken, there’s an issue with the wiring, or there could be an actual problem causing too much air to be pushed into the engine. Addressing this involves checking the sensor and the surrounding wires for any damage, ensuring everything’s properly connected, and replacing any faulty parts to get your car running smoothly again.
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How to fix P012D – learn from mechanics
I looked into P012D service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Subaru P012D
Vehicle Information 2017 Subaru WRX STI 2.5L Turbocharged
Issue + Repair History
- Vehicle experiencing intermittent stalling and reduced engine power.
- OBD2 trouble code P012D indicating high condition within the turbo/supercharger inlet pressure sensor circuit.
- No previous repairs mentioned.
Other OBD2 Codes + Test Results
- No additional OBD2 codes reported.
- Live data showed inconsistent intake pressure readings.
Mechanic Suggestions
- Inspected turbo/supercharger inlet pressure sensor and wiring harness for damage.
- Tested sensor connector for corrosion.
- Checked ground connections for integrity.
- Verified fuse related to sensor circuit.
- Confirmed air filter condition.
Final Fix
- Replaced turbo/supercharger inlet pressure sensor.
- Conducted thorough inspection of wiring harness and repaired damaged wires.
- Cleared trouble codes and performed test drive to confirm issue resolution.
Case #2: Honda P012D
Vehicle Information 2016 Honda Civic Type R 2.0L Turbocharged
Issue + Repair History
- Vehicle experiencing intermittent stalling and reduced engine power.
- OBD2 trouble code P012D indicating high condition within the turbo/supercharger inlet pressure sensor circuit.
- No previous repairs mentioned.
Other OBD2 Codes + Test Results
- No additional OBD2 codes reported.
- Live data showed inconsistent intake pressure readings.
Mechanic Suggestions
- Inspected turbo/supercharger inlet pressure sensor and wiring harness for damage.
- Tested sensor connector for corrosion.
- Checked ground connections for integrity.
- Verified fuse related to sensor circuit.
- Confirmed air filter condition.
Final Fix
- Replaced turbo/supercharger inlet pressure sensor.
- Conducted thorough inspection of wiring harness and repaired damaged wires.
- Cleared trouble codes and performed test drive to confirm issue resolution.
Case #3: Volkswagen P012D
Vehicle Information 2018 Volkswagen Golf R 2.0L Turbocharged
Issue + Repair History
- Vehicle experiencing intermittent stalling and reduced engine power.
- OBD2 trouble code P012D indicating high condition within the turbo/supercharger inlet pressure sensor circuit.
- No previous repairs mentioned.
Other OBD2 Codes + Test Results
- No additional OBD2 codes reported.
- Live data showed inconsistent intake pressure readings.
Mechanic Suggestions
- Inspected turbo/supercharger inlet pressure sensor and wiring harness for damage.
- Tested sensor connector for corrosion.
- Checked ground connections for integrity.
- Verified fuse related to sensor circuit.
- Confirmed air filter condition.
Final Fix
- Replaced turbo/supercharger inlet pressure sensor.
- Conducted thorough inspection of wiring harness and repaired damaged wires.
- Cleared trouble codes and performed test drive to confirm issue resolution.
How to diagnose P012D
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Brief Explanation |
|---|---|
| Inspect sensor and wiring | Look for any physical damage or signs of wear that could impact the sensor’s accuracy. |
| Test sensor connector | Check for corrosion or poor contact that might cause false high readings. |
| Check ground connections | Ensure all related ground connections are secure, as poor grounding can affect sensor readings. |
| Verify air filter condition | A clogged air filter can sometimes impact air pressure readings, so it should be inspected and replaced if necessary. |
| Replace sensor and repair wiring | Faulty sensors or damaged wiring should be replaced to ensure accurate intake pressure readings. |
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko