P0107 Ford 5.0L – Test a Ford MAP Sensor
Problems with your manifold absolute pressure sensor can arise from age or heat or the combination of the two, leading to your Ford MAP Sensor causing a P0107 Ford trouble code. The OBDII check engine trouble code is about the manifold absolute pressure (MAP) sensor sending too high of a signal to the Powertrain Control Module (PCM). This sensor’s job is to measure the vacuum at the intake manifold and translate this vacuum or pressure signal to a voltage your PCM understands.
Unfortunately, something is preventing your MAP sensor from operating correctly and sending a signal to your PCM that is usable. Because you have a check engine light on your dash that signifies your P0107 OBDII code, the voltage being sent to the PCM is far too low.
Today I’ll be showing you how to test the MAP sensor in a 1996 Ford E-150 with a 5.0 liter engine and VIN code of N. The MAP sensor is located behind the mass air flow sensor (MAF) and intake hose mounted to the factory throttle body.
To test the pressure sensor in your 5.0 liter Ford you will need to locate the sensor, part number E7FZ-12A644-A. This MAP sensor is connected by a three pin weatherproof connector that you will be testing for voltage and signal.
Symptoms of a Failed MAP Sensor
- Bad idle
- Idle Surge
- Engine wont stay on
- Poor gas mileage
What we are testing for
When you depress the accelerator pedal and the throttle plate opens further, the MAP sensor should be sending a signal to the PCM. The decreasing vacuum should be translated to a higher voltage to the PCM, so we will be testing for power and ground and finally the signal. Unfortunately because the Ford MAP sensor for this year and generation of 5.0 liter engine does not use the typical voltage style signal.
The 5.0 liter Ford engine found in this early OBDII vehicle is also found in previous OBDI trucks and vans. In order to test the signal, you will need a scan tool to read the PCM real time or have a multimeter that’s capable of reading Hertz frequency. If you do not own a scan tool for your OBDII 5.0 liter Ford engine, you will also need a vacuum hand pump with a gauge.
How to Test your MAP Sensor for Power
Because the P0107 Ford OBDII DTC trouble code relates to the MAP sensor seeing too much vacuum pressure. Because this Ford 5.0 liter MAP sensor is but a three wire connector, it will comprise of power, low reference (ground) and the MAP signal circuit.
Locate your Manifold Absolute Pressure sensor and unplug the three pin weatherproof connector. Inspect the diagram above for the proper pin identification of the Ford 5.0 MAP connector.
To learn how to test your Ford 5.0 liter MAP sensor, you will need a voltmeter or multimeter to check the circuits at each wire. To check for power and the low reference signal (ground) you will be placing the negative post of your multimeter to the negative terminal of your battery. With the key set to the “ON” position but without the engine started, check PIN B for the switched power circuit.
With the key set to the “ON” position, PIN B should have 5 volts of switched power going to it. If you do not have 5 volts of power here, chances are other sensors in your vehicle are also having problems. Check the wiring and make sure there is no wire rot or exposed wire that could cause a short.
Next check for the ground signal, which should be PIN A that grounds PIN B. If there is no ground here, this also could be causing problems elsewhere in your Ford van, because these are PCM supplied power and ground signals that are responsible for all sensors.
How to Test your MAP Sensor for Signal
The last wire on the three pin MAP sensor connector is PIN C which is the signal reference that is causing your P0107 OBDII DTC code. Using your multimeter or voltmeter, measure the voltage at the MAP sensor at idle.
With the key set to the “ON” position, measure PIN C to see what the sensor is telling your PCM. Because the P0107 Ford OBDII code is for too high of a signal, measuring it at idle should be around 152 Hz from this last pin. If this value is much higher, this would be a good sign that your MAP sensor is bad and must be replaced.
Anywhere from the 152 Hz range to 149 is acceptable, any value that is lower actually means that the MAP sensor sees too much pressure. Always remember that as the vacuum increases the voltage decreases at the MAP sensor, as the vacuum decreases the voltage increases.
Replace this MAP sensor with the Ford part number E3ZF12A644A1A, E3ZF12A644A2A, E3ZF12A644B1A, and E3ZZ12A644A