P1107

Diagnostic Chart:

Wiring Diagram:

Circuit Description
The Manifold Absolute Pressure (MAP) sensor responds to changes in the intake manifold pressure (vacuum). A 5 volt reference is applied to the sensor on the 5 volt reference circuit. A variable resistor moves in relation to the manifold pressure and a voltage signal is sent back to the VCM on the MAP sensor signal circuit. This voltage signal will vary from 1.0-1.5 volts at closed throttle to 4.0 - 4.6 volts at wide open throttle (low vacuum). The VCM utilizes the MAP signal and the throttle position in order to determine the correct amount of fuel delivered to the engine. This Diagnostic Trouble Code (DTC) is a type D DTC.

Conditions for Setting the DTC
The following conditions will set the DTC:

1. No TP sensor faults are set.
2. The engine is operating.
3. The TP is at least 0% when engine speed is no more than 800 RPM.
4. Or the TP is at least 12.5% when the engine speed is greater than 800 RPM.

Action Taken When the DTC Sets
The VCM turns on the Malfunction Indicator Lamp (MIL) when this DTC is reported and 1 failure has occurred. The VCM substitutes a calculated value for the MAP sensor value so that acceptable performance is maintained.

Conditions for Clearing the MIL/DTC
The VCM turns the MIL off after 3 consecutive driving trips without a fault condition present. A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 40°F from the start-up coolant temperature and the engine coolant temperature exceeds 160°F during that same ignition cycle) or the scan tool clearing feature has been used.

Diagnostic Aids
An intermittent open in the MAP sensor signal circuit or the 5 volt reference circuit will result in a DTC P1107. With the ignition ON and the engine off, the manifold pressure is equal to the atmospheric pressure with the signal voltage high. The VCM uses this information as an indication of the altitude of the vehicle. Comparison of this reading with a known good vehicle using the same sensor is a good way to check the accuracy of a suspect sensor. Readings should be the same ±0.4 volt. Refer to Intermittents. - Intermittent Malfunctions

Important:
^ The electrical connector must remain securely fastened.
^ Disconnect the sensor from the bracket and twist the sensor by hand (only) in order to check for intermittent connections. The output changes greater than 0.1 volt indicates a bad connector or connection. If OK, replace the sensor.
^ After removing the MAP sensor from the intake manifold, replace the MAP Sensor to intake manifold seal.

Test Description
The numbers below refer to the step numbers on the diagnostic table.

2. This step determines if the DTC P1107 is the result of a hard failure or an intermittent condition.
3. Jumpering the 5 volt reference to the signal circuit will determine if sensor is at fault or if there is a problem with the VCM, or the wiring.
4. The scan tool may not display 5 volts. The important thing is that the VCM recognized the voltage as more than 4 volts, indicating that the VCM and MAP sensor signal circuit are OK.