The OBD2 code P012C is triggered when the engine control module (ECM) detects a low input signal from the turbocharger or supercharger inlet pressure sensor circuit. This sensor measures the pressure of the air entering the turbocharger or supercharger, a crucial parameter for optimal engine performance and efficiency.
A low signal could indicate an issue within the sensor circuit, such as damaged wires, poor connections, or a faulty sensor, leading to engine performance issues like poor acceleration, misfiring, or even causing the vehicle to enter limp mode.
P012C quick overview
| Meaning | P012C: Turbocharger/Supercharger Inlet Pressure Sensor Circuit Low |
| Is it serious? | Yes, this issue can significantly affect engine performance and should be addressed promptly to avoid potential engine damage. |
| Possible causes | – Faulty turbocharger/supercharger inlet pressure sensor – Damaged or corroded wiring and connectors in the sensor circuit – Poor ground connections – Faulty ECM (less common) |
| How to diagnose? | Inspect the sensor and its wiring harness for visible damage or corrosion. Test the sensor connector for good contact and corrosion. Check all ground connections related to the sensor circuit for integrity. Verify the condition of the air filter, as a clogged filter can impact pressure readings. Replace the sensor and repair any damaged wiring as needed. |
P012C Meaning
When you get a P012C code, it means your car’s computer is getting a weaker signal than expected from the sensor that checks the air pressure going into your turbocharger or supercharger. This can make your car feel sluggish, cause it to stall, or not perform as well as it should.
The problem could be with the sensor itself, the wires connected to it, or even something as simple as a dirty air filter affecting the pressure. Fixing it usually involves checking the sensor and the wiring for any damage and making sure everything’s clean and connected right.
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How to fix P012C – learn from mechanics
I looked into P012C 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: Ford P012C
Vehicle Information Ford F-150 2015 3.5L EcoBoost
Issue + Repair History
- Vehicle experiencing poor acceleration and entering limp mode intermittently.
- OBD2 trouble code P012C indicating low 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 fluctuating 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.
- Repaired damaged wiring harness.
- Conducted test drive to confirm issue resolution.
Case #2: Honda P012C
Vehicle Information Honda Civic 2017 1.5L Turbo
Issue + Repair History
- Vehicle experiencing engine misfiring and poor performance.
- OBD2 trouble code P012C indicating low 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: Toyota P012C
Vehicle Information Toyota Supra 2020 3.0L Turbocharged
Issue + Repair History
- Vehicle experiencing intermittent stalling and reduced engine power.
- OBD2 trouble code P012C indicating low 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 P012C
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 signs of physical damage, corrosion, or wear that could impair the sensor’s function. |
| Test sensor connector | Ensure the connector is in good condition and making proper contact without any signs of corrosion. |
| Check ground connections | Verify that all ground connections are secure and intact, as poor grounding can affect sensor signals. |
| Verify air filter condition | A clogged air filter can impact air pressure and sensor readings, so it should be checked and replaced if necessary. |
| Replace sensor and repair wiring | If diagnostics indicate a faulty sensor or damaged wiring, replace the sensor and repair the wiring to resolve the issue. |
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