Code P0068: MAP/MAF – Throttle Position Correlation

Understanding Error Code P0068

Your PCM, or powertrain control module, uses three sensors to determine the current airflow and adjust the fuel and timing as necessary. Each of these sensors must be working properly for your engine to run optimally:

• Manifold pressure sensor
• Mass airflow sensor
• Throttle position sensor

Each of these sensors are used to determine the necessary amount of airflow. The mass airflow sensor is typically found between the throttle body and air cleaner. The throttle position sensor is on the opposite side of the throttle plate and controls the amount of airflow in relation to the throttle. Finally, the manifold pressure sensor is used to correct air pressure in relation to temperature, altitude and humidity.

When working properly, these three sensors work together to communicate with your engine and adjust the airflow as necessary. When one or more sensor isn’t working properly, or is sending conflicting messages about the current air/fuel ratio, your computer system will immediately trigger error code P0068. It isn’t capable of determining which signal is correct, so any discrepancy needs to be resolved for correct airflow.

Common Symptoms

The biggest sign of an OBD-II scanner error code P0068 problem is a rough idle. Because of the differences in airflow readings, your engine typically won’t receive the ideal airflow. This results in choking, sputtering and overall difficult idling. Your Check Engine light will also illuminate to alert you to the problem. Because of the number of sensors related to your air intake, you may have other OBD-II error codes triggered. In that case, you can expect other symptoms related to other issues in your air/fuel ratio.

Possible Causes

Your airflow system is crucial for the optimal air/fuel ratio in your engine. Because of this, there are many integral parts for successful airflow. A damaged component, cracked hose or improper seal anywhere in these systems could result in error code P0068.

One possible cause is a dirty air cleaner. When your air cleaner becomes clogged it won’t allow the airflow you need. Leaks in the intake manifold also prevent the necessary flow of air. Obstructions or damage to hoses and vents can greatly reduce the effectiveness of your intake manifold.

Another possible cause, particularly if you aren’t experiencing a rough idle, is an electrical issue. Corroded or frayed wires, loose connections and damaged sensors are all issues that could be causing your trouble code P0068.

Repair Solutions

The most common causes are simply dirty or clogged components, so your first solution should be removing any debris or buildup from your air cleaner, sensors and air intake. Cleaning these parts with the right cleaning solutions can improve their effectiveness and offer a low-cost repair.

If that doesn’t solve your issue, check all the clamps and piping between your mass airflow sensor and throttle body. This is a common area for air leaks. Vacuum lines are another area that can become cracked or loose.

After these issues, check your electrical system. Test the voltage of each sensor to ensure they are all receiving electricity. Test each sensor and, if need be, replace faulty sensors. A faulty manifold pressure sensor or throttle position sensor could cause an issue with the entire air intake system.
After you’ve walked through every possible cause and repair solution, you have a better idea of what does the code P0068 mean? This error code can dramatically affect your engine, so it’s important to find the right solution promptly.