P0107 - Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
The MAP sensor has the biggest say in fuel metering calculations. A signal voltage that's off by as little as 0.1 volt will have a big effect on engine performance. As with most 5.0-volt sensors, the acceptable range of signal voltages is between 0.5 and 4.5 volts. Code 107 means the Engine Computer is seeing less than 0.5 volts. When you unplug the sensor, that is also detected, and the computer "injects" its own value to run on. It picks that value by looking at other sensor readings and operating conditions. The engine will run better, but not perfectly.
Most sensor circuits use a pull-up resistor to force the signal wire to go to 5.0 volts if it is cut or has some other break. That sets a different fault code for "MAP voltage too high". Most of the time the only way to get a "voltage low" fault code is for the signal wire to grounded. Inspect the wiring harness first, especially where it lays on the sharp edge of a metal bracket or where it rubs back and forth on the inner fender.
Thursday, June 1st, 2017 AT 4:47 PM