For 1990-2009 cars
Engine Controls Component Views
Engine Controls Schematics

### Circuit Description

The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor wiring includes the following circuits:

• | A 5-volt reference circuit

• | A low reference circuit

• | A MAP sensor signal circuit

The powertrain control module (PCM) supplies 5 volts to the MAP sensor on a dedicated 5-volt reference circuit. The PCM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The PCM 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 PCM monitors the MAP sensor signal for voltage outside of the normal range.

If the PCM detects a MAP sensor signal voltage that is excessively low, DTC P0107 sets.

### Conditions for Running the DTC

• | DTC P0122, P0123 are not set.

• | The engine is running.

• | The engine speed is less than 1,000 RPM.

| OR

• | The throttle angle is more than 15 percent when the engine speed is more than 1,000 RPM.

### Conditions for Setting the DTC

The ECM detects that the MAP sensor voltage is less than 0.1 volt for more than 6 seconds.

### 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.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls
2 |

1. Turn ON the ignition, with the engine OFF.
2. Observe the MAP sensor parameter with the scan tool.

Is the voltage less than the specified value?

0.1 V

Go to Step 4

Go to Step 3

3 |

1. Observe the Freeze Frame/Failure Records for this DTC.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Intermittent Conditions

4 |

1. Turn OFF the ignition.
2. Disconnect the manifold absolute pressure (MAP) sensor electrical connector.
3. Turn ON the ignition, with the engine OFF.
4. Measure the voltage from the 5-volt reference circuit of the MAP sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage more than the specified value?

4.8 V

Go to Step 5

Go to Step 6

5 |

1. Connect a 3-amp fused jumper wire between the 5 volt reference circuit of the MAP sensor and the signal circuit of the MAP sensor.
2. Observe the MAP sensor parameter with the scan tool.

Is the voltage more than the specified value?

4.9 V

Go to Step 8

Go to Step 7

6 | Test the 5 volt reference circuit between the powertrain control module (PCM) and the MAP sensor for an open or 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 12 | Go to Step 9
7 | Test the MAP sensor signal circuit between the PCM and the MAP sensor for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9
8 | Test for an intermittent and for a poor connection at the 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 12 | Go to Step 10
9 | Test for an intermittent and for a poor connection at the PCM. 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 12 | Go to Step 11
10 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 12 | --
11 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | --
12 |

1. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 13

13 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List | System OK