What is Fault Code P0068?
Fault code P0068, applicable to all car manufacturers, means “MAP/MAF – Throttle Position Correlation“.
Background Information: The Manifold Absolute Pressure (MAP) sensor measures the pressure (vacuum) in the intake manifold. The powertrain control module (PCM) then uses the difference between the intake manifold pressure and atmospheric pressure (which is linearly related to engine load) as a basis for determining the basic fuel injection quantity to help the engine achieve the optimal air-fuel ratio under different loads. The Mass Airflow (MAF) sensor converts airflow into an electrical signal and sends it to the electronic control unit (ECU) as one of the basic signals for determining fuel injection quantity. The Throttle Position (TP) sensor transmits the throttle opening angle as an electrical signal to the electronic control unit (ECU) as one of the basic parameters for controlling engine fuel injection. This fault code will appear if the ECU detects a significant discrepancy between the load calculated by the Manifold Absolute Pressure (MAP) sensor/Mass Airflow (MAF) sensor and the load calculated by the Throttle Position (TP) sensor.
Symptoms of Fault Code P0068
- Unstable engine idle
- Difficulty starting the engine
- Reduced power and responsiveness during acceleration
- Increased fuel consumption
- Engine may stall immediately after starting
- Engine malfunction indicator light illuminates on the dashboard
Main Causes of Fault Code P0068
- Throttle body contamination (soot, oil, carbon deposits)
- Air leaks in the intake system (vacuum lines, hoses)
- Faulty Mass Airflow (MAF) sensor
- Damaged Manifold Absolute Pressure (MAP) sensor
- Faulty Throttle Position Sensor (TPS)
- Circuit or connector problems
- Engine Control Module (PCM/ECM) malfunction
Fault Code P0068 in Different Vehicles
P0068 in Chevrolet: In Chevrolet models (such as Malibu, Cruze), the P0068 error is usually related to a dirty throttle valve and MAF sensor malfunction. Models equipped with Ecotec engines require damper adjustment after cleaning.
P0068 in Volkswagen: In Volkswagen models (Passat, Golf), this error may occur due to a faulty electronic throttle control module. Precise sensor calibration and adaptation are usually required using VCDS. Audi P0068: In Audi vehicles, this error occurs when there is a mismatch between the MAP and MAF sensors. This is especially common in turbocharged models, where the sensors operate under high load.
Dodge P0068: In Dodge vehicles (Charger, Durango), this error may be caused by a faulty ETC module.
Chrysler P0068: Chrysler vehicles often experience P0068 due to poor contact in the TPS or MAF sensor connectors. Oxidation testing and connector cleaning are required.
How to diagnose P0068 error code?
- Connect an OBD2 diagnostic scanner and read the error codes. Note any related errors (e.g., P0101, P0106, P0121).
- Check the air filter condition and for contaminants in the intake system.
- Perform a visual inspection and intake manifold leak test.
- Check the MAF, MAP, and TPS sensors using a multimeter and scanner.
- If necessary, perform throttle body cleaning and adjustment using a diagnostic tool.
Possible Causes and Diagnostic Methods
| Possible Cause | How to Check? |
|---|---|
| Throttle body contamination | Visual inspection, clean with throttle body cleaner |
| Intake system leak | Vacuum hose inspection, leak test |
| MAF sensor malfunction | OBD2 scanner, output signal and power voltage test |
| MAP sensor issue | Voltage and resistance measurement, comparison with standards |
| TPS malfunction | Check output signal while moving the damper |
| Electrical wiring irregularities | Visual inspection, check wires with a multimeter |
| ECM error | Check additional specifications, update or replace the unit |
Tools needed: OBD2 diagnostic scanner, multimeter, screwdriver and wrench set, throttle body cleaner and rags
How to fix error code P0068? (Solutions to the Problem)
Simple Fixes
- Clean carbon deposits from the throttle body
- Replace or clean the air filter
- Check and replace vacuum hoses to prevent leaks
- Check sensor connectors and repair contacts
- Reset the error code after resolving the cause
In-depth Diagnostic and Repair Solutions
- Replace the faulty MAF, MAP, or TPS sensor
- Reflash or replace the ECM/PCM to prevent malfunctions
- Check power circuits, grounds, and signal lines
- Electronic throttle body adaptation
Troubleshooting by Symptoms
| Symptom | Possible Solution |
|---|---|
| Unstable idle | Clean the throttle body, check the MAF (Mass Airflow Sensor) |
| Loss of power | MAF/MAP replacement, leak repair |
| Difficult starting | TPS check, throttle flap adaptation |
| Increased fuel consumption | Diagnosis of the three sensors |
Frequently Asked Questions
Can you drive with a P0068 error code?
It is not recommended. Inconsistent sensor data can lead to unstable engine operation, increased fuel consumption, and even engine stalling while driving.
What happens if I don’t fix the P0068 error?
Ignoring the error can lead to further damage to intake system components, shorten engine life, and increase repair costs.
Can I fix the P0068 error myself?
Yes, if the problem is related to throttle valve contamination or loose hoses. However, if the sensor or control unit is faulty, professional help may be needed.
Do I need to adapt the throttle body after cleaning?
Yes, in most vehicles equipped with electronic dampers, adaptation must be performed using a diagnostic scanner after cleaning or replacement.
Is the P0068 error related to the MAF sensor?
Yes, the P0068 error often occurs due to inconsistent MAF, MAP, and TPS readings. MAF failure can be one of the main causes.
Which car models are affected?
The P0068 fault code frequently appears in models such as the Ford Fiesta, Chrysler 300M, Porsche Macan, Chevrolet Trailblazer, and Buick Verano, especially those with high mileage or recent repair history.
P0068 Related OBD2 Errors
P0101 – Mass or Volume Air Flow A Circuit Range/Performance
P0106 – Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance
P0121 – Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance
Important! Even if symptoms do not appear immediately, error P0068 requires immediate diagnosis. Neglecting maintenance may lead to further damage to the engine or intake system components. During the initial diagnosis, pay attention to the cleanliness of the throttle valve and the proper functioning of the sensors. After cleaning or replacing parts, adjustments should be made to ensure the error does not reappear.