GM Service Manual Online
For 1990-2009 cars only

Object Number: 1248064  Size: MF
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 has the following circuits:

    • 5-volt reference circuit
    • Low reference circuit
    • MAP sensor signal circuit

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

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

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage

Conditions for Running the DTC

    • The engine is running.
    • DTC P0068, P0120, P0122, P0123, P0220, P0222, P0223, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176 are not set.
    • The throttle angle is more than 0 percent when 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.
    • DTC P0107 runs continuously when the above conditions are met.

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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 Engine Control Module Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Start the engine.
  2. Monitor the DTC Information with the scan tool.

Is DTC P0651 also set?

--

Go to DTC P0651

Go to Step 3

3

Observe the manifold absolute pressure (MAP) sensor parameter with the scan tool.

Is the voltage is less than the specified value?

0.1 V

Go to Step 5

Go to Step 4

4

  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.

Does the DTC fail this ignition?

--

Go to Step 5

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

5

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 13

Go to Step 6

6

  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, with a DMM.

Is the voltage more than the specified value?

4.8 V

Go to Step 7

Go to Step 8

7

  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 11

Go to Step 9

8

Test the 5-volt reference circuit between the engine control module (ECM) and the MAP sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

9

Test the MAP sensor signal circuit between the ECM and 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 13

Go to Step 10

10

Test for an intermittent and for a poor connection at the ECM. 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 13

Go to Step 12

11

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

Did you complete the replacement?

--

Go to Step 13

--

12

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 13

--

13

  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 14

14

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK