Circuit Description
The manifold absolute pressure (MAP) sensor is a transducer that varies resistance according to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits:
| • | 5-volt reference circuit |
| • | Low reference circuit |
| • | MAP sensor signal circuit |
The engine control module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The ECM supplies a bias voltage measuring between 4-6 volts on the MAP sensor signal circuit. The ECM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used in order to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The ECM monitors the MAP sensor signal for voltage outside of the normal range.
If the ECM detects a MAP sensor signal voltage that is excessively low, DTC P0107 sets.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
The MAP sensor voltage is less than 0.14 volts for more than 1 second.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
| • | The ECM supplies voltage to various components using three separate 5-volt reference circuits. They are designated A, B, and C. |
| • | Through three terminals on the ECM, the 5-volt reference A circuit is distributed to the following components: |
| - | One circuit supplies voltage to the accelerator pedal position (APP) sensor 1. |
| - | Another circuit is spliced, and supplies voltage to the air conditioning (A/C) pressure sensor and the fuel tank pressure (FTP) sensor. |
| - | The last circuit is spliced through a 5-volt reference splice pack, and supplies voltage to the camshaft position (CMP) sensor. The mass air flow (MAF) sensor, the MAP sensor, and the exhaust gas recirculation (ERG) valve. |
| - | A circuit short or component failure that causes the 5-volt reference A system voltage to be pulled low or high, may affect any of the components that receive voltage from the 5-volt reference A circuit. |
If this DTC is determined to be intermittent, refer to Intermittent Conditions .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connect End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||||||
2 |
Is the voltage less than the specified value? | 0.14 V | Go to Step 4 | Go to Step 3 | ||||||||||||
Does the DTC fail this ignition? | -- | Go to Step 4 | Go to Diagnostic Aids | |||||||||||||
4 | Test for an intermittent and for a poor connection at the manifold absolute pressure (MAP) sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 5 | ||||||||||||
5 |
Is the voltage more than the specified value? | 4.8 V | Go to Step 6 | Go to Step 13 | ||||||||||||
6 | Measure the voltage from the 5-volt reference circuit of the MAP sensor to a good ground with a DMM. Is the voltage more than the specified value? | 4.8 V | Go to Step 18 | Go to Step 7 | ||||||||||||
7 |
Does the voltage measure more than the specified value after any of the components are disconnected? | 4.8 V | Go to Step 17 | Go to Step 8 | ||||||||||||
8 |
Is the voltage more than the specified value? | 4.8 V | Go to Step 12 | Go to Step 9 | ||||||||||||
9 |
Refer to Circuit Testing in Wiring Systems. Does continuity exist? | -- | Go to Step 15 | Go to Step 10 | ||||||||||||
10 | Test for continuity between each of the three 5-volt reference A circuits and a body ground, at the ECM connector. Refer to Circuit Testing in Wiring Systems. Does continuity exist? | -- | Go to Step 16 | Go to Step 11 | ||||||||||||
11 | Test the 5-volt reference circuit between the 5-volt reference splice pack and the ECM for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 14 | ||||||||||||
12 | Test the 5-volt reference circuit between the 5-volt reference splice pack and the MAP sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 14 | ||||||||||||
13 | Test the MAP signal circuit between the ECM and the MAP sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 14 | ||||||||||||
14 | Test for shorted terminals and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19 | ||||||||||||
15 | Repair the circuit to circuit short. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 20 | -- | ||||||||||||
16 | Repair the short to ground in the affected 5-volt reference circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 20 | -- | ||||||||||||
17 | Replace the component for which the voltage changed. Refer to one of the following replacement procedures: Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||||||||
18 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||||||||
19 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||||||||
20 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 21 | ||||||||||||
21 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||||||
