If the engine in your Jeep Grand Cherokee experiences difficulty starting or does not run smoothly, the problem may be caused by the wrong ratio of air to fuel. Optimal fuel metering requires input from several sensors. Find out what to do if a vehicle diagnostic returns error code P0100 MAF Circuit Malfunction.
How Do You Know If You Have a Bad Mass Air Flow Sensor?
A bad mass air flow sensor provides inaccurate data or fails to provide the engine control unit with air data for controlling fuel injection. Inaccurate air flow readings can cause the fuel injection system to provide too much or too little fuel, causing an engine to run rich or lean.
Diagnostics are helpful for pinpointing sensor problems, particularly with Jeep Grand Cherokees that rely on speed density systems. Check the error codes to determine which sensors are malfunctioning. It is unlikely to get a P0100, P0101, P0102, P0103 or P0014 code because most Jeep vehicles do not have mass air flow sensors. Other Jeep Grand Cherokee auto parts such as the intake air temperature sensor, manifold absolute pressure sensor and oxygen sensors provide speed density data that informs the engine control unit and allows for proper adjustment of fuel levels.
Where to Find Your MAF Sensor on a Jeep Grand Cherokee
The IAT and MAP sensors in a Jeep Cherokee send digital signals that correspond to mass air flow sensor readings. MAF sensors are typically located between the air filter housing and intake manifold on vehicles that are equipped with these components. It is a good idea to disconnect the negative battery cable before removing MAF or speed density sensors for inspection, cleaning or replacement.
Speed density sensors are also located under the hood. Some of these parts are easier to access than others. The IAT sensor is located inside a hose, and it is necessary to remove a cover and detach a snorkel to gain access to the sensor for inspection or cleaning. The MAP sensor is located near the top of the firewall. Be sure to use MAF sensor cleaner or other solutions formulated for these components.
How to Quickly Test If You MAF Sensor Is Working Properly
A scan tool is helpful for measuring engine air flow at different RPMs and comparing readings taken by current sensors and known good sensors. Use a digital multimeter to check voltage or an oscilloscope to measure frequencies. These tools and sensor cleaner or a replacement MAF sensor or speed density system components such as MAP, TPS, CPS, CTS, O2 or IAC sensors may be necessary to address performance issues. It is also important to regularly switch out Jeep Grand Cherokee oil filters and air filters.
The Jeep Grand Cherokee ZJ, WJ, WK and WK2 models do not have MAF sensors. Problems with the ratio of air to fuel in a vehicle that relies on speed-density measurements may be caused by other sensors. Reference diagnostic error codes and test relevant sensors to identify the cause of poor engine performance or problems that affect fuel metering.