GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

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

DTC P0108: Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference

P0107, P0405, P0452, P0651, P2106, P2110

P0107

P0108, P0651, P2076

P0106

MAP Sensor Signal

P0107

P0107

P0108

P0106

Low Reference

--

P0108, P2106, P2110

--

P0106

Typical Scan Tool Data

MAP Sensor

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Engine operating in Closed Loop

Parameter Normal Range: 32-48 kPa

5-Volt Reference

10 kPa

10 kPa

50 kPa

MAP Sensor Signal

10 kPa

10 kPa

104 kPa

Low Reference

--

98 kPa

104 kPa*

* Internal ECM damage may occur if the circuit is shorted to B+.

Circuit/System 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 engine control module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM 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 detects a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM detects 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 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 throttle position (TP) sensor is greater than 28 percent.

Conditions for Running the DTC

P0107

    • DTCs P0122 and P0123 are not set.
    • The TP sensor is greater than or equal to 0 percent while the engine speed is less than 1,000 RPM.
        OR
    • The TP sensor is greater than 5 percent while the engine speed is greater than 1,000 RPM.
    • The ignition 1 voltage is greater than 11 volts.
    • The DTC runs continuously when the above conditions are met.

P0108

    • DTCs P0122 and P0123 are not set.
    • The engine has been running for greater than 10 seconds.
    • The TP sensor is less than 15 percent while the engine speed is less than 2,500 RPM.
        OR
    • The TP sensor is less than 35 percent while the engine speed is greater than 2,500 RPM.
    • The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

P0107

The ECM detects that the MAP is less than 12 kPa for greater than 5 seconds.

P0108

The ECM detects that the MAP is greater than 103 kPa for greater than 5 seconds.

Action Taken When the DTC Sets

    • DTC P0107 and P0108 are Type A DTCs.
    • The BARO will not be updated.

Conditions for Clearing the DTC

DTC P0107 and P0108 are Type A DTCs.

Diagnostic Aids

    • If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected.
    • The scan tool 5 volt reference parameter should display between 4.8-5.2 volts.

Reference Information

Schematic Reference

Engine Controls Schematics

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 23738-A Vacuum Pump

Circuit/System Verification

  1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0651 is not set.
  2. If P0651 is set, refer to DTC P0641 or P0651.
  3. Turn all accessories OFF.
  4. Important: In extreme cold weather conditions ice may form in the vacuum source to the MAP sensor and may set a DTC. Inspect the MAP sensor and the vacuum source for ice, moisture, or other restrictions.

  5. Engine running, observe the scan tool MAP Sensor parameter. The reading should be between 32-48 kPa.
  6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the vacuum hose at the MAP sensor. Connect the J 23738-A to the vacuum hose.
  2. Engine running, verify that 15-20 in Hg of vacuum is available to the MAP sensor.
  3. If not within the specified range, repair the restriction in the vacuum hose to the MAP sensor.
  4. Ignition OFF, connect the vacuum hose to the MAP sensor. Disconnect the harness connector at the MAP sensor.
  5. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal A and ground.
  6. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  7. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground.
  8. If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  9. Verify the scan tool MAP sensor pressure parameter is less than 12 kPa.
  10. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  11. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool MAP sensor parameter is greater than 102 kPa.
  12. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  13. If all circuits test normal, test or replace the MAP sensor.

Component Testing

  1. Ignition OFF, perform one of the following applicable procedures.
  2. • Disconnect the vacuum supply hose from the MAP sensor
    • Remove the MAP sensor from the intake manifold
  3. Ignition ON, observe and record the scan tool MAP sensor pressure data parameter. This is the first MAP sensor reading.
  4. With the J 23738-A apply 5 in Hg (17 kPa) of vacuum to the MAP sensor. Observe and record the scan tool MAP sensor pressure data parameter. This is the second MAP sensor reading.
  5. Subtract the second MAP sensor reading from the first MAP sensor reading. Verify the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.
  6. If not within the specified range, replace the MAP sensor.
  7. With the J 23738-A apply 10 in Hg (34 kPa) of vacuum to the MAP sensor. Observe and record the scan tool MAP sensor pressure data parameter. This is the third MAP sensor reading.
  8. Subtract the third MAP sensor reading from the first MAP sensor reading. Verify the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.
  9. If not within the specified range, replace the MAP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Manifold Absolute Pressure Sensor Replacement
    •  Control Module References for ECM replacement, setup, and programming