P0107

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 signal circuit. This voltage signal varies from 1.0-1.5 volts at closed throttle to 4.0-4.5 volts at wide open throttle (low vacuum). The VCM utilizes the MAP signal and throttle position in order to determine the correct amount of fuel delivered to the engine.

CONDITIONS FOR SETTING THE DTC

^ No TP sensor DTCs

^ Engine running

^ Throttle Position is at least 0% when engine speed is no more than 800 RPM

^ Throttle Position is at least 12.5% when engine speed is greater than 800 RPM

ACTION TAKEN WHEN THE DTC SETS

The VCM turns ON the MIL when DTC P0107 is reported and 1 failure has occurred. The VCM substitutes a calculated value for the MAP sensor value so an acceptable driving condition is maintained.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The VCM turns the MIL OFF after 3 consecutive drive trips when the test has Run and Passed and not Failed.

^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle).

^ Use the scan tool Clear Information function.

^ Disconnect the VCM battery feed for 30 seconds.

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 (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 within 0.4 volt.

Refer to Symptoms. Testing and Inspection

IMPORTANT: The electrical connector must remain securely fastened.

IMPORTANT: After removing the MAP sensor from the intake manifold, replace the MAP Sensor to intake manifold seal.

Remove the MAP sensor. Twist the sensor by hand (only) in order to check for any intermittent connections. Output changes greater than 0.1 volt indicates a bad connector or connection. If OK, replace the sensor.

TEST DESCRIPTION

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

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

3. By jumping the 5 volt reference to the signal circuit, this step determines if the sensor is at fault, or it there is a problem with the VCM or 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 signal circuit are OK.

10. The VCM terminals CLR 12 and CLR 27 are spliced together inside the VCM. When checking the 5 volt reference for a short to ground, both the 5 volt reference circuits and all the components on the 5 volt reference circuits must be checked.