P0107

DTC P0107 MAP Sensor Circuit Low Voltage




Circuit Description
The Manifold Absolute Pressure (MAP) sensor is mounted in the intake manifold. The MAP sensor measures pressure changes within the intake manifold which is an indication of engine load. The MAP sensor has a 5.0 volt reference, a ground, and a signal circuit. When the manifold pressure is low (high vacuum) the sensor output voltage is low. When the manifold pressure is high (low vacuum) the sensor output voltage is high.

The MAP sensor voltage (depending on altitude) can range from 1.0 - 1.5 volts at idle (high vacuum) to 4.0 - 4.9 volts at wide open throttle (low vacuum).

This DTC is designed to detect MAP signal voltages lower than possible in a normally operating map sensor.

Conditions for Running the DTC
- No active TP sensor DTCs
- The engine is running
- The throttle position is greater than 0% with an engine speed below 800 RPM
OR
The throttle position is greater than 12.5% with an engine speed above 800 RPM

Conditions for Setting the DTC
The MAP voltage is below 0.04 volts for more than 1 second.

Action Taken When the DTC Sets
- The VCM illuminates the MIL (Malfunction Indicator Lamp) if a failure is detected during 2 consecutive key cycles.
- The VCM will set the DTC and records the operating conditions at the time the diagnostic fails. The VCM stores the failure information in the scan tools Freeze Frame and/or the Failure Records.

Conditions for Clearing the MIL/DTC
- The VCM turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed.
- 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 is more than 70 °C (158 °F) during the same ignition cycle).
- Use the scan tool Clear Information function.

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.

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.

An intermittent may be caused by any of the following conditions:
- A poor connection
- Rubbed through wire insulation
- A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis.

If a repair is necessary, then refer to Wiring Repairs or Connector Repairs.

Steps 1 - 3:

Steps 4 - 9:

Steps 10 - 16:

Steps 17 - 21:

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. This step determines if the VCM is able to provide a 5 volt reference to the MAP sensor.
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 circuits are OK.
10. The 5 volt reference of the VCM supply is shared by the MAP, FTP, TP, and EGR position sensors. A short to ground at ANY of the sensors 5 volt reference circuits OR an internally shorted sensor may cause this DTC to set.
11. In order to determine the location of a shorted 5 volt reference supply disconnect the sensors one at a time beginning with the TP sensor.


If the test lamp goes OFF when a sensor is disconnected a shorted sensor is indicated.