GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage diagnostic monitors the MAP sensor response to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits:

    • A 5-volt reference circuit
    • A low reference circuit
    • A signal circuit

The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The signal circuit returns a portion of the reference voltage to the PCM depending on the pressure inside the intake manifold. The PCM also provides a ground on the low reference circuit. The PCM should detect a low signal voltage at a low MAP, such as during idle or 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 wide open throttle (WOT). The PCM monitors the MAP sensor signal for voltage outside of the normal range.

Engine Condition

MAP kPa

MAP Signal Voltage

Manifold Vacuum

Idle

Low

Low

High

Deceleration

Low

Low

High

Ignition ON, Engine OFF

High

High

Zero

Wide-Open Throttle

High

High

Low

Conditions for Running the DTC

    • Intake Air Temperature is greater than 5°C (41°F).
    • Engine Coolant Temperature is between -8 and +110°C (18-230°F).
    • Barometric pressure is greater than 75 kPa.

Conditions for Setting the DTC

The MAP sensor voltage signal is less than 0.2 volts.

Actions Taken When the DTC Sets

    • The Powertrain Control Module (PCM) illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with the fault active.
    • The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

    • The PCM tuns OFF the MIL after 3 consecutive trips without a fault,
    • The PCM clears a History DTC after 40 consecutive warm-up cycles without a fault.
    • Perform the scan tool Clear DTC Information function.

Diagnostic Aids

The MAP sensor shares a sensor ground circuit with the Intake Air Temperature sensor (IAT) and Engine Coolant Temperature sensor (ECT).

An intermittent malfunction may be caused by a fault in the MAP sensor circuits. Inspect the wiring harness and components for an intermittent condition. Refer to Intermittent Conditions .

If a DTC P0107 cannot be duplicated, the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC set.

Test Description

The numbers below refer to the step numbers in the Diagnostic Table.

  1. The Diagnostic System Check prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

  2. This step checks for the correct reference circuit voltage.

  3. Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P0107 diagnostic can be monitored on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If a DTC P0107 appears in the Not Ran Since Code Cleared list, the DTC P0107 diagnostic has not yet run. When the DTC P0107 does not appear in the Not Ran Since Code Cleared list, the DTC P0107 diagnostic has run. If the MIL is NOT illuminated, and there is no Pending DTC Status in DTC Information, the DTC P0107 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. DO NOT forget that the Not Ran Since Code Cleared list only indicates that the test has run, not whether the test passed or failed. The DTC Information screen must be checked for Current or Pending status, in order to determine the outcome of the diagnostic test involved.

Step

Action

Value(s)

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. Turn ON the ignition, leaving the engine OFF.
  2. Install a scan tool.
  3. Select the MAP sensor parameter on the scan tool.

Is the MAP sensor display at or below the specified value?

0.2 V

Go to Step 4

Go to Step 3

3

  1. Turn ON the ignition, leaving the engine OFF.
  2. Perform the scan tool Clear DTC Information function.
  3. Operate the vehicle within the Freeze Frame conditions as noted.

Is the MAP sensor display below the specified value, or has this DTC set?

0.2 V

Go to Step 4

Go to Diagnostic Aids

4

  1. Turn OFF the ignition.
  2. Disconnect the MAP sensor electrical connector.
  3. Turn ON the ignition, leaving the engine OFF.
  4. Measure the voltage from the 5 volt reference circuit to ground (harness side) with a DMM.

Is the voltage near the specified value?

5 V

Go to Step 5

Go to Step 7

5

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the 5 volt reference circuit and the signal circuit on the harness side of the connector.
  3. Turn On the ignition, leaving the engine OFF.

Is the scan tool MAP sensor voltage parameter near the specified value?

5 V

Go to Step 6

Go to Step 8

6

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

Is the action complete?

--

Go to Step 11

--

7

  1. Check for an open or a short to ground in the 5 volt reference circuit between the PCM and the MAP sensor.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

--

Go to Step 11

Go to Step 9

8

  1. Check for an open or a short to ground in the MAP sensor signal circuit between the PCM and the MAP sensor.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

--

Go to Step 11

Go to Step 9

9

  1. Inspect the PCM and the MAP sensor electrical connectors for faulty terminal contact.
  2. Repair as necessary.

Was a repair necessary?

--

Go to Step 11

Go to Step 10

10

Replace the PCM. Refer to Powertrain Control Module Replacement

Is the action complete?

--

Go to Step 11

--

11

  1. Turn OFF the ignition.
  2. Remove the DOME fuse for 30 seconds.
  3. Install the DOME fuse.
  4. Reset the radio clock time. Refer to Radio/Audio System Description and Operation in Entertainment.
  5. Start the engine.
  6. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or until the DTC P0107 diagnostic test has run.

Does the DTC run and pass?

--

Go to Step 12

--

12

  1. Perform the scan tool Clear DTC Information function and road test the vehicle within the Freeze Frame conditions that set the DTC.
  2. Review the scan tool data and check for DTCs. The repair is complete if no DTCs are stored.

Are any DTCs displayed on the scan tool?

--

Go to the Applicable DTC Table

System OK