For 1990-2009 cars

### Circuit Description

The manifold absolute pressure (MAP) sensor responds to changes in intake manifold pressure which gives an indication of the engine load. The MAP sensor has a 5-volt reference circuit, and a signal circuit. The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit and provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the signal circuit which is relative to the pressure changes in the manifold. With low manifold absolute pressure such as during idle or deceleration, the PCM should detect a low MAP sensor signal voltage. With high manifold absolute pressure such as ignition ON, with the engine OFF or wide-open throttle, the PCM should detect a high MAP sensor signal voltage. Certain vehicle models will also use the MAP sensor in order to calculate the barometric pressure (BARO) when the ignition is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at wide-open throttle. The PCM monitors the MAP sensor signal for voltage outside of the normal range. If the PCM detects a MAP signal voltage that is intermittently low, DTC P1107 will set.

### Conditions for Running the DTC

• | DTCs P0121, P0122, or P0123 are not set.

• | The ignition is ON.

• | The throttle angle is more than 0 percent when the engine speed is less than 1,000 RPM.

• | The throttle angle is more than 10 percent when the engine speed is more than 1,000 RPM.

### Conditions for Setting the DTC

The MAP sensor voltage is intermittently less than 0.1 volts.

### Action Taken When the DTC Sets

• | The control module stores the DTC information into memory when the diagnostic runs and fails.

• | The malfunction indicator lamp (MIL) will not illuminate.

• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.

• | The driver information center, if equipped, may display a message.

### Conditions for Clearing the DTC

• | 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 non-emission related diagnostic.

• | Clear the DTC with a scan tool.

### Diagnostic Aids

• | Inspect the MAP sensor vacuum source for leaks, restrictions or poor connections.

• | If the condition is intermittent, refer to Intermittent Conditions .

### Test Description

The number below refers to the step number on the diagnostic table.

1. Many intermittent open or shorted circuits come and go with harness/connector movement caused by vibration, engine torque, and bumps. This step attempts to recreate this condition.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Engine Controls Schematics
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls
2 |

1. Install a scan tool.
2. Start the engine.
3. Monitor the Diagnostic Trouble Code (DTC) Information using the scan tool.

Does the scan tool indicate that DTC P1635 or P0107 is current?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3 | With a scan tool observe the MAP sensor voltage. Does the scan tool indicate that the voltage is less than the specified value? | 0.1 V | Go to Step 5 | Go to Step 4
4 |

1. Turn OFF the ignition.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool observe the MAP sensor voltage, while moving the MAP sensor connector, the PCM connector, and the wiring harness related to the MAP sensor.

Does the scan tool indicate that the MAP sensor voltage is less than the specified value and holding?

0.1 V

Go to Step 5

Go to Diagnostic Aids

5 |

1. Turn OFF the ignition.
2. Disconnect the 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.

Does the voltage measure near the specified value?

5 V

Go to Step 6

Go to Step 7

6 | 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. Does the scan tool indicate that the voltage is near the specified value? | 5 V | Go to Step 9 | Go to Step 8
7 | Test the 5-volt reference circuit of the MAP sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10
8 | Test the signal circuit of the MAP sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10
9 | Inspect for poor connections 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 11 | Go to Diagnostic Aids
10 | Inspect for poor connections 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 11 | Go to Diagnostic Aids
11 |

1. Use the scan tool in order to clear the DTCs.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

Go to Step 12

Go to Step 2

12 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List | System OK