Circuit Description
The manifold absolute pressure (MAP) sensor is a pressure sensor. The control module supplies the MAP sensor a reference voltage, signal, and ground circuits. When manifold vacuum is low, the MAP sensor signal voltage rises to a value near the reference voltage, and the MAP sensor signal voltage decreases when the manifold vacuum increases. The control module monitors the MAP sensor signal circuit voltage in order to calculate the vacuum within the intake manifold.
Certain vehicle models will also use the MAP sensor in order to calculate the barometric pressure (BARO) when the ignition switch is turned ON and the engine is NOT cranked. This BARO reading may also be updated whenever the engine is operated at wide open throttle (WOT).
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 |
| • | Engine is running. |
| • | The throttle position is greater than or equal to 0 percent with an engine speed below 800 RPM |
| OR |
| • | The throttle position is greater than or equal to 12.5 percent 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 control module illuminates the malfunction indicator lamp (MIL) the first time the diagnostic runs and fails. |
| • | The control module will set the DTC and records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tools Freeze Frame/Failure Records. |
Conditions for Clearing the MIL or DTC
| • | The control module 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. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle. |
| • | Use a scan tool in order to clear the DTCs. |
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: 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.
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 in Wiring Systems.
If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if DTC P0107 is the result of a hard failure or an intermittent condition.
-
This step determines if the VCM is able to provide a 5 volt reference to the MAP sensor.
-
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.
-
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.
-
The sensor connectors must remain disconnected while the VCM C3 connector remains connected for this step. The VCM terminals C3 12 and C3 27 are spliced together inside the VCM. When checking the 5 volt reference circuit for a short to ground, both the 5 volt reference circuits must be checked.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the scan tool Capture Info to save the Freeze Frame and Failure Records for reference. The control module's data is deleted once the Clear Info function is used. Did you perform the Powertrain On-Board Diagnostic (OBD) system Check? | -- | ||||||||
Does the scan tool display a MAP sensor voltage less than the specified value? | 0.25 V | |||||||||
Is the voltage more then the specified value? | 4.7 V | |||||||||
Does the scan tool display a MAP sensor voltage more than the specified value? | 4.7 V | |||||||||
5 | The DTC is intermittent. Are any additional DTCs stored? | -- | Go to the applicable DTC table. | Go to Diagnostic Aids | ||||||
6 | Check for a poor connection at the MAP sensor. Did you find a problem? | -- | ||||||||
7 | Check for an open MAP sensor signal circuit. Did you find a problem? | -- | ||||||||
8 | Check for a short to ground in the MAP sensor signal circuit. Did you find a problem? | -- | ||||||||
9 |
Did you find a problem? | -- | ||||||||
Did the voltage read more than the specified value after disconnecting one of the sensors? | 4.7 V | |||||||||
11 | Is the suspect sensor the EGR sensor? | -- | ||||||||
12 | Check for a short between the 5 volt reference circuit and the EGR feed control circuit. Did you find a problem? | -- | ||||||||
13 |
Is the action complete? | 4.7 V | -- | |||||||
Is the test lamp ON? | -- | Go to Step 17 | Go to Step 15 | |||||||
15 | Check for a poor connection at the VCM. Did you find a problem? | -- | ||||||||
16 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Is the action complete? | -- | -- | |||||||
17 | Repair the circuit as necessary. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the action complete? | -- | -- | |||||||
18 |
Is the action complete? | -- | -- | |||||||
19 |
Does the scan tool indicate the diagnostic Passed? | -- | ||||||||
20 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK |
