P0107

Manifold Absolute Pressure (MAP) Sensor Circuit:

Circuit Description
The PCM uses the Manifold Absolute Pressure (MAP) sensor output voltage to assist in controlling fuel delivery and ignition timing. The PCM supplies a 5 volt reference signal voltage and a ground to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the PCM knows the manifold pressure. A lower pressure (low voltage) output voltage will be about 1.0 to 1.5 volts at idle. While higher pressure (high voltage) output voltage will be about 4.5 to 4.8 at Wide Open Throttle (WOT). The MAP sensor is also used to record barometric pressure during engine start up and at wide open throttle. This allows the PCM to make adjustments for different altitudes.

Conditions for Setting the DTC
- The MAP is less than 14 kPa.
- The engine speed is less than 1200 RPM.
- The Throttle Position (TP) sensor is greater than 16%.
- The above conditions are met for 0.2 seconds.
- DTC P0122 or P0123 is not set.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
- The PCM will substitute a fixed MAP value and use throttle position to control three fuel delivery. The scan tool will not show the defaulted value.

Conditions for Clearing the MIL/DTC
- The MIL will turn "OFF" after three consecutive ignition cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTCs can be cleared by using a scan tool.

Diagnostic Aids
With the ignition "ON" and the engine "OFF'. the manifold pressure is equal to atmospheric pressure and the signal voltage will be high. This information is used by the PCM as an indication of vehicle altitude. Comparison of this reading with a known good vehicle with the same sensor is a good way to check the accuracy of a "suspect" sensor. Readings should be the same ±0.4 volt.
Whenever a DTC P0107 is intermittent, refer to Manifold Absolute Pressure Sensor Output Check Table for further diagnosis.

NOTE: After repairs use the scan tool Fuel Trim Reset function to reset long term fuel trim to 128 (0%).

DTC P0107 - Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage (1 Of 2):

DTC P0107 - Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage (2 Of 2):

Test Description
Numbers below refer to the step numbers on the Diagnostic Table.
1. The OBD System Check prompts the Technician to complete some basic checks and store the Freeze Frame Data and the Failure records on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. This information on the scan tool can be referred to later.
2. This step determines if DTC P0107 is the result of a hard failure or an intermittent condition.
3. Jumpering harness terminals "B" to "C" (signal circuit to 5 volts) will determine if the sensor is at fault or if there is a problem with the PCM or wiring.
6. The scan tool may not display 5 volts. The important thing is that the PCM recognizes the voltage as more than 4 volts, indicating that the PCM and the MAP signal circuit are OK. A test light that illuminates indicates a short to ground in the signal circuit.
7. An open or short to ground in the 5V reference circuit could also set additional DTCs.
11. Before replacing the PCM, check terminals for improper mating, broken locks, or physical damage to the wiring harness. Replacement PCM must be reprogrammed. Refer to the latest Techline information for programming procedures.