Poor engine performance is one of the most common symptoms associated with a turbo/supercharger inlet pressure (TCIP) sensor circuit malfunction. However, these symptoms may also stem from other faulty components in the engine.
Thankfully, modern vehicles are equipped with on-board diagnostic (OBD) systems to help you or a mechanic figure out what issues may be persisting in your ride. P012d is just one of the several engine trouble codes related to a possible fault in the TCIP circuit.
What Does the P012d Code Mean?
Diagnostic Trouble Code (DTC) P012d stands for “Turbo/Supercharger Inlet Pressure Sensor Circuit High.” The code is logged once the vehicle’s powertrain control module (PCM) perceives that the signal from the TCIP sensor is too high. A signal that is too high refers to the voltage or to an obviously inaccurate reading as compared to barometric pressure (BARO).
Turbochargers and superchargers increase the pressure in the intake manifold. This pulls additional air into the combustion chamber to help boost engine power. Both turbo and superchargers have an inlet where filtered air gets in. The vehicle’s powertrain control module (PCM) uses this inlet pressure sensor to monitor and regulate intake pressure.
Once the PCM detects a TCIP sensor signal reading that is beyond the manufacturer-specified limit, it will set the P012d code.
Our brief technical discussion about the supercharger inlet pressure sensor can help you gain more information that’s especially helpful if you’re planning to fix P012d yourself.
Note: The definition of code P012d may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.
What are the Possible Causes of the P012d Code?
Here are some possible triggers of the P012d code:
- Failed inlet pressure sensor
- Faulty manifold absolute (MAP) sensor
- Wiring and connector issues
- Malfunctioning PCM
What are the Common Symptoms of a P012d Code?
Here the common symptoms related to this error code:
- Activated check engine light
- Poor engine performance
- Stalling
- Increased fuel consumption
- Engine noises
- Vehicle may switch to limp mode
How to Diagnose the P012d Code
Diagnosing engine trouble and identifying the problem that triggered the code may not be easy for everyone. For instance, there are several oxygen sensor malfunction codes that share similar causes and symptoms. In most cases, it is best to take your vehicle to an auto shop to get an accurate diagnosis.
If you are interested in learning about what the diagnostic procedure might involve, we recommend getting a vehicle-specific repair manual or an online repair database subscription. These resources contain factory repair information that may give you a better understanding of this code and more.
How to Fix the P012d Code
There is no universal solution for any trouble code. Although P012d is a generic code, repair procedures may still vary depending on your vehicle’s specific year, make, and model. For example, repair procedures for a P012d on a Ford F150 may not work on other vehicle makes and models.
Before attempting to fix this code on your own, be sure to read your vehicle’s repair manual to help you identify the P012d fix that may work for your vehicle. Alternatively, you may also subscribe to an online repair database.
The Supercharger Inlet Pressure Sensor
Under normal operation the absolute highest pressure that can exist in the supercharger intake manifold is equal to Barometric Pressure (BARO). That’s BEFORE the supercharger compresses the intake charge and forces it into the plenum feeding the cylinders. In other words, the pressure at the supercharger inlet can never be higher than ambient atmospheric pressure.
Atmospheric pressure occurs in this measured part of the intake stream whenever the vehicle is operated at wide-open throttle (WOT) or when the key is on while the engine is off.
The lowest manifold pressures occur when the vehicle is idling or decelerating (throttle closed, engine spinning). The supercharger inlet pressure can range from 20 kPa (about 3 psi) to as much as BARO (14.7 psi at sea level).
For supercharger pressure control, this input must be accurate.
The supercharger inlet pressure sensor measures the intake stream pressure between the throttle body and the supercharger.
This measured pressure is affected by four different factors:
- engine speed
- throttle opening
- air temperature
- barometric pressure (BARO)
This sensor provides a signal voltage that varies relative to pressure changes. The engine control module (ECM/PCM) supplies a 5 volt reference feed and monitors the signal circuit voltage, which varies with pressure. The algorithm is written to detect anomalies in the pressure reading that indicate the reading is false or unreliable.
Get a Dependable New MAP Sensor Today
While a malfunctioning inlet pressure sensor commonly sets the P012d code, the trouble code can also appear because of a faulty manifold absolute pressure sensor. Don’t delay in replacing the faulty part to avoid more engine-related issues. Order a replacement MAP sensor from CarParts.com for high performance that you can depend on.
Make CarParts.com your first and only choice for competitively priced, high-performance MAP sensors. We’re proud of our extensive catalog of products that fit many different vehicle makes and models. Locate the most suitable replacement MAP sensor by accessing our website’s built-in vehicle selector and plugging in the details of your car or truck. Complete your order with just a few taps on your mobile phone. If you live in the continental US and place your order before 12 p.m. ET, your new MAP sensor will arrive at your doorstep in only several business days.
Don’t wait for the ailing MAP sensor to stop working. Shop for an MAP sensor today!
Products Mentioned in this Guide
Turbocharger
Supercharger Kit
Intake Manifold
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Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.
