Applies to: Mercedes-Benz GLA, C-Class, E-Class, Sprinter, 2.1L Diesel (2005–2023)
The P012C00 fault code on Mercedes-Benz vehicles indicates an issue with the intake air pressure sensor. When this sensor fails or sends incorrect readings, it can trigger the Check Engine Light, put your car into limp mode, and cause rough idling or hesitation.
🔍 What Does Code P012C00 Mean?
P012C00 translates to “Sensor Intake Air Pressure has a Malfunction.” This means the ECU is detecting a signal outside the normal operating range from the intake air pressure sensor.
- Common Symptoms: Check Engine Light (CEL), loss of power, poor fuel economy, limp mode.
- Related Systems: Intake manifold pressure, turbocharger boost, and air-fuel mixture control.
🧰 How to Diagnose and Fix Mercedes P012C00
In this case, the vehicle used in the video is a 2016 Mercedes GLA 2.1 Diesel. The same steps apply to other Mercedes diesel engines from 2005–2024.
Step 1: Confirm the Code
Use a professional scan tool like the iCarsoft CR ULTRA P to read the stored code. Confirm P012C00 appears under the Engine Control Module (ECM).
Step 2: Inspect the Sensor and Wiring
- Locate the intake air pressure sensor on the manifold.
- Check for loose connections, damaged wiring, or corrosion.
- Ensure there’s 5V reference and ground continuity to the sensor.
Step 3: Replace the Sensor
If the wiring checks out and power is present, the sensor itself is most likely faulty. Replace with an OEM-quality sensor only — cheap aftermarket sensors often fail prematurely or provide inaccurate readings.
Step 4: Reset Adaptations
After replacing the sensor, use your iCarsoft CR ULTRA P to clear the fault code and reset learned adaptations:
- Connect CR ULTRA P via Bluetooth or OBD2 cable.
- Go to Special Functions → Teaching Process → Reset Adaptions.
- Follow on-screen prompts and clear all stored DTCs.
Once completed, restart the engine and verify the fault code does not reappear.
💡 Why Use the iCarsoft CR ULTRA P?
The iCarsoft CR ULTRA P is a high-end diagnostic tool that provides intelligent VIN scanning, live data, and ECU-level functions for Mercedes-Benz and other brands. It allows you to perform advanced operations like:
- Injector coding
- DPF regeneration
- Throttle adaptation
- ABS bleeding and service resets
- Full system topology mapping
👉 Check out the CR ULTRA P here
📖 Real-World Example
A GLA 220d owner reported intermittent limp mode and a P012C00 code even after cleaning the EGR and boost sensor. After testing the harness with the CR ULTRA P and confirming voltage presence, replacing the intake air pressure sensor with an OEM part solved the issue immediately. Resetting the adaptations cleared the code permanently.
❓FAQs
Can I drive with code P012C00?
It’s not recommended. The engine may enter limp mode and reduce power output to protect itself from potential boost or fueling errors.
Will cleaning the sensor fix it?
Sometimes, if the sensor is only lightly contaminated. However, if the internal circuit is faulty, replacement is the only fix.
Does the sensor need coding?
No, the intake air pressure sensor doesn’t require coding. But you should clear the code and reset the ECU adaptations after replacement using a diagnostic tool.
Is the CR ULTRA P compatible with other Mercedes models?
Yes. It supports all major Mercedes-Benz platforms (C-Class, E-Class, GLA, Sprinter, GLC, etc.) from 2005–2024.
