For 1990-2009 cars

Schematic Reference: Engine Controls Schematics

### Circuit Description

The Manifold Absolute Pressure (MAP) sensor is mounted to the top of the intake manifold. The MAP sensor measures pressure changes within the intake manifold which are an indication of engine load. The MAP sensor has a 5.0 volt reference circuit, a ground and a signal circuit.

The PCM compares the MAP sensor signal activity with throttle angle and RPM. If the PCM detects a large MAP change without sensing a change in throttle angle and RPM, this DTC will set.

### Conditions for Setting the DTC

• | DTCs P0107, P0108, P0121, P0122 and P0123 not set.

• | Engine operating.

• | ASR/TCS not in a traction event (If so equipped).

• | Engine speed does not change more than 100 RPM.

• | TP sensor angle does not change more than 5%.

• | EGR position does not change more than 25%.

• | IAC position, at a steady state.

• | No change (steady state) in A/C clutch, power steering signal, brake signal, and transmission position.

• | PCM detects a substantial change in MAP, without being proceeded by a large change in throttle angle and RPM.

• | All conditions stable for 0.5 second.

• | All conditions met for 4.5 seconds.

### Action Taken When the DTC Sets

• | The PCM will illuminate the Malfunction Indicator Lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails.

• | The PCM will record operating conditions at the time the diagnostic fails. The first time the diagnostic fails, this information will be stored in Failure Records. If the diagnostic reports a failure on the second consecutive drive trip, the operating conditions at the time of failure will be written to Freeze Frame and the Failure record will be updated.

• | The PCM will use TP sensor values to calculate MAP.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.

• | A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• | PCM battery voltage is interrupted.

• | Using a Scan tool.

### Diagnostic Aids

An intermittent may be caused by the following:

• | Mis-routed harness.

• | Rubbed through wire insulation.

• | Broken wire inside the insulation.

For intermittents, refer to Symptoms .

### Test Description

Number(s) below refer to step numbers on the diagnostic table.

1. Erratic engine vacuum caused by a base engine problem or a misfire condition should be diagnosed first.

2. When moving related connectors, visually/physically inspect connectors for the following:

• | Poor mating of the connector halves or a terminal not fully seated in the connector body (backed out).

• | Improperly formed or damaged terminals. All connector terminals in the related circuits should be carefully reformed or replaced to insure proper contact tension.

• | Poor terminal to wire connection. Inspect for poor crimps, crimping over wire insulation rather than the wire.

• | Dirt or corrosion on terminals. Inspect connector seals for being there and for being damaged.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Is DTC P0300 also set? | -- | Go to DTC P0300 Engine Misfire Detected | Go to Step 3
3 |

1. Start and idle the engine.
2. Using a scan tool, select MAP from the Engine 1 Data List.

Is MAP varying more than the specified amount?

6.3 kPa

Go to Step 4

Go to Step 9

4 |

1. Turn the ignition ON, engine OFF.
2. Move the MAP sensor electrical connector, the harness and the PCM connectors (by hand only) while observing the scan tool display.

Is the MAP value affected by moving the harness or connectors?

--

Go to Step 12

Go to Step 5

5 | Important: This value will vary with altitude. Refer to Test Description. Does the scan tool display the MAP value shown? | 100 kPa | Go to Step 6 | Go to Step 13
6 |

1. Remove the MAP sensor from the intake manifold but leave the electrical harness connected.
2. Connect a hand operated vacuum pump to the MAP sensor.
3. Observe the MAP display while slowly applying vacuum up to 20 inch Hg as indicated on the pump gauge. Each 1 inch of vacuum applied should result in a 3 to 4 kPa drop in the MAP sensor value on the scan tool and the value should change smoothly with each increase in vacuum.

Did the MAP value change smoothly through the entire range of the test without any erratic readings?

--

Go to Step 13

Go to Step 7

7 | Apply 20 inch Hg vacuum to the MAP sensor. Is the MAP sensor reading the same or less than the specified value? | 34 kPa | Go to Step 8 | Go to Step 13
8 | Disconnect the vacuum source from the MAP sensor. Does the MAP sensor reading return to its original value? | -- | Go to Step 9 | Go to Step 13
9 |

1. Turn the ignition ON, engine OFF, review Freeze Frame and/or Failure Records data for this DTC and note parameters.
2. Turn the ignition OFF for 15 seconds.
3. Start the engine and operate the vehicle within the conditions required for this diagnostic to run, and as close to the conditions recorded in Freeze Frame/Failure Records as possible. Special operating conditions that need to be met before the PCM will run this diagnostic, where applicable, are listed in Conditions for Setting the DTC.
4. Using the scan tool, select DTC, Specific, then enter the DTC number which was set.

Does the scan tool indicate that this diagnostic failed this ignition?

--

Go to Step 10

Go to Diagnostic Aids

10 |

1. Check the MAF sensor harness for incorrect routing.
2. Near secondary ignition or components.
3. Other high voltage components.
4. Solenoids, relays, motors.
5. If incorrect routing is found, correct harness routing.

Was a problem found and corrected?

--

Go to Step 16

Go to Step 11

11 | Check for a plugged or leaking vacuum supply to the MAP sensor. Was a problem found and corrected? | -- | Go to Step 13 | Go to Step 14
12 | Check for the following conditions and repair as necessary:

• | Electrical connector terminals for poor connections, improper contact tension or poor terminal to wire connection.

• | Rubbed through wire insulation.

• | Broken wire inside the insulation.

• | Mis-routed harness.

Is action complete?

--

Go to Step 16

Go to Step 10

13 | Replace the MAP sensor. Is action complete? | -- | Go to Step 16 | --
14 | Check the connections at the PCM. Was a problem found and corrected? | -- | Go to Step 16 | Go to Step 15
15 | Important:: Replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | Go to Step 16 | --
16 |

1. Using the scan tool, select DTC, Clear Info.
2. Start the engine and idle at normal operating temperature.
3. Select DTC, Specific, then enter the DTC number which was set.
4. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 17

Go to Step 2

17 | Using the scan tool, select Capture Info, Review Info. Are any DTCs displayed that have not been diagnosed? | -- | Go to the applicable DTC table | System OK