P0107

DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low (Signal Voltage Low - High Vacuum):

MAP Sensor Circuit:

Circuit Description
The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum). The VCM receives this information as a signal voltage that will vary from about 1-1.5 volts at idle to 4-4.6 volts at Wide Open Throttle (WOT) (low vacuum).

A Tech 1 scan tool displays manifold pressure in volts. Low pressure (high vacuum) reads a low voltage while a high pressure (low vacuum) reads a high voltage.

If the MAP sensor fails the VCM will substitute a fixed MAP value and use the Throttle Position (TP) sensor to control fuel delivery.

DTC P0107 Will Set When
^ Engine is less than 1000 RPM.
^ Manifold pressure reads less than 14 kPa, for 2 seconds. OR
^ Engine speed is greater than 1000 RPM.
^ Throttle angle over 21%.
^ Manifold pressure less than 14 kPa, for 2 seconds.

Action Taken (VCM will default to)
MAP will default to 90.8 kPa.

DTC P0107 Will Clear When
Conditions for fault are no longer present and Tech 1 clear DTCs function is used or 50 ignition switch keycycles have passed with no further faults or ignition switch is turned "OFF" and Fuse #9 (ECM B) fuse is removed for 10 seconds.

DTC Chart Test Description
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This step determines if DTC P0107 is the result of a hard failure or an intermittent condition.

2. Jumpering harness terminals "B" to "C", (5 volts to signal circuit) will determine if the sensor is at fault, or if there is a problem with the VCM or wiring.

3. The Tech 1 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 CKT 432 are OK.

4. This will determine if 5.0 volts are present at the sensor.

Diagnostic Aids
An intermittent open in CKT 432 or CKT 474 will result in a DTC P0107.

With the ignition "ON" and the engine "OFF," the manifold pressure is equal to atmospheric pressure with the signal voltage high. This information is used by the VCM as an indication of vehicle altitude.

Comparison of this reading with a known good vehicle using the same sensor is a good way to check accuracy of a "suspect" sensor. Readings should be the same ± .4 volt. Also, "MAP Output Check" in "Control Module System" can be used to test the MAP sensor.

Refer to "Intermittents". - Intermittent Malfunctions

Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connections. Output changes greater than .1 volt indicates a bad connector or connection. If OK, replace sensor.

NOTICE: Make sure electrical connector remains securely fastened.