P1107

DTC P1107 MAP Sensor CKT Intermittent 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 intermittent low voltage signals on the MAP sensor signal circuit.

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

Conditions for Setting the DTC
The VCM detects an intermittent low MAP sensor voltage while the engine is running.

Action Taken When the DTC Sets
The VCM stores the DTC in History if the VCM detects an Intermittent problem.

Conditions for Clearing the MIL/DTC
- 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.

Diagnostic Aids
An intermittent open or intermittent short to ground in the MAP sensor signal circuit or the 5 volt reference circuit could 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.

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 - 7:

Steps 8 - 9:

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. If the MAP sensor voltage is less than 0.5 volts then the condition is present.
3. If any other non-intermittent DTCs are set go there first.
6. The engine must be running in order to observe the MAP sensor signal voltage.