GM Service Manual Online
For 1990-2009 cars only

Object Number: 293709  Size: MF
A/C Refrigerant Pressure Sensor, TP Sensor, Map Sensor, ECT Sensor, IAT sensor
Engine Controls Components
OBD II Symbol Description Notice
ESD Notice

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, a ground, and a signal circuit.

The MAP sensor contains a diaphragm which changes resistance based on pressure. When manifold pressure is low, or the vacuum is high, sensor output voltage is low. When manifold pressure is high, or the vacuum is low, sensor output voltage is high. MAP sensor voltage, depending on altitude, can range from below 2 volts at idle to above 4 volts at wide open throttle (WOT) or with the engine not running.

The MAP sensor signal is also used at initial key-up to determine barometric pressure (BARO).

Conditions for Running the DTC

    • No TP sensor DTCs present.
    • The engine is running.
    • Idle speed is steady.
    • Throttle angle above 0%, if engine speed is less than 1000 RPM.
    • Throttle angle above 10%, if engine speed is greater than 1000 RPM.

Conditions for Setting the DTC

    • The MAP sensor signal voltage is less than 0.1 volt.
    • Above conditions present for approximately 10 seconds.

Action Taken When the DTC Sets

    • The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

    • The PCM turns the MIL Off after three consecutive drive trips that the diagnostic runs and does not fail.
    • A last test failed (current DTC) clears when the diagnostic runs and does not fail.
    • A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
    • Use a scan tool in order to clear the MIL/DTC.
    • Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description , Clearing Diagnostic Trouble Codes.

Diagnostic Aids

Notice: Use the connector test adapter kit J 35616-A for any test that requires probing the following items:

   • The PCM harness connectors
   • The electrical center fuse/relay cavities
   • The component terminals
   • The component harness connector
Using this kit will prevent damage caused by the improper probing of connector terminals.

If DTC P0107 cannot be duplicated, the information included in the Fail Records data can be useful in determining since the DTC was last set.

If the problem is intermittent, refer to Intermittent Conditions .

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table:

  1. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

2

Observe the MAP value displayed on the scan tool.

Is MAP value near the specified value?

0V

Go to Step 4

Go to Step 3

3

  1. Turn the key to Off, wait 15 seconds then turn the key to On.
  2. Review and record the Failure Records data.
  3. Operate the vehicle within Failure Records conditions.
  4. Using a scan tool, monitor Specific DTC info for DTC P0107.

Does the scan tool indicate DTC P0107 failed this ign?

--

Go to Step 4

Refer to Diagnostic Aids.

4

  1. Turn off the engine, then turn the key to On.
  2. Disconnect the MAP sensor electrical connector.
  3. Jumper the 5 volt reference A circuit and the MAP signal together at the MAP sensor harness connector.
  4. Observe the MAP value displayed on the scan tool.

Is the MAP value greater than the specified value?

4.6V

Go to Step 10

Go to Step 5

5

  1. Remove the jumper.
  2. Connect a test light J 35616-200 between B+ and the MAP sensor signal circuit at the MAP sensor harness connector.
  3. Observe the MAP value displayed on the scan tool.

Is the MAP value near the specified value?

4.6V

Go to Step 6

Go to Step 8

6

  1. Turn the key to Off.
  2. Disconnect the PCM.
  3. Check the 5 volt reference A circuit for an open or short to ground.
  4. If the 5 volt reference A circuit is open or shorted to ground, repair it as necessary. Refer to Intermittents and Poor Connections Diagnosis

Was a problem found and corrected?

--

Go to Step 12

Go to Step 7

7

  1. Check the 5 volt reference A circuit for a poor connection at the PCM.
  2. If a problem is found, repair as necessary. Refer to Intermittents and Poor Connections Diagnosis

Was a problem found and corrected?

--

Go to Step 12

Go to Step 11

8

  1. Turn the key to Off.
  2. Disconnect the PCM.
  3. Check the MAP signal circuit for an open, short to ground, or short to the sensor ground circuit.
  4. If the MAP sensor signal circuit is open or shorted to ground, repair it as necessary. Refer to Intermittents and Poor Connections Diagnosis

Was a problem found and corrected?

--

Go to Step 12

Go to Step 9

9

  1. Check the MAP sensor signal circuit for a poor connection at the PCM.
  2. If a problem is found, repair as necessary. Refer to Intermittents and Poor Connections Diagnosis .

Was a problem found and corrected?

--

Go to Step 12

Go to Step 11

10

Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement .

Is the action complete?

--

Go to Step 12

--

11

Replace the PCM.

Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 12

--

12

  1. Clear DTCs with the scan tool.
  2. Turn the key to Off and wait 15 seconds
  3. Operate vehicle within the conditions that are required for this diagnostic to run. Refer to Conditions for Running the DTC.

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

--

Go to Step 13

Go to Step 2

13

Review Captured Info using the scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to the applicable DTC table

System OK