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

High Resistance

Open

Short to Voltage

Signal Performance

5-Volt Reference

P0107, P0452, P0532, P0641

P0106, P0107

P0107

P0108, P0533, P0641

P0106, P0107

MAP Sensor Signal

P0107

P0106, P0107

P0107

P0108

P0106, P0107, P1101

Low Reference

--

P0106, P0108

P0106, P0108

--

P0106, P0108

Typical Scan Tool Data

MAP Sensor

Circuit

Normal Range

Short to Ground

Open

Short to Voltage

5-Volt Reference

--

0 kPa

0 kPa

127 kPa

MAP Sensor Signal

10-104 kPa

0 kPa

0 kPa

127 kPa

Low Reference

--

--

80-126 kPa

--

Circuit Description

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the greatest pressure that can exist in the intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is on while the engine is off. Under these conditions, the ECM uses the MAP sensor to determine the current BARO. The least manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 10 kPa, when pressures are less, to as great as 104 kPa, depending on the current BARO. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

Conditions for Running the DTC

P0107

    • The ignition is ON.
        OR
    • DTCs P0121, P0122, P0123, P0220, P0222, P0223, P2135, are not set.
    • The throttle angle is greater than 0 percent when the engine speed is less than 1,000 RPM.
        OR
    • The throttle angle is greater than 13 percent when the engine speed is greater than 1,000 RPM.
    • This DTC runs continuously within the enabling conditions.

P0108

    • DTCs P0121, P0122, P0123, P0220, P0222, P0223, P2135, are not set.
    • The engine has been running for a period of time that is determined by the start-up engine coolant temperature (ECT). The time ranges from 8 seconds at less than -30°C (-22°F) to 3 seconds at greater than 30°C (86°F).
    • The throttle angle is less than one percent when the engine speed is less than 1,200 RPM.
        OR
    • The throttle angle is less than 20 percent when the engine speed is greater than 1,200 RPM.
    • This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC

P0107

The ECM detects that the MAP sensor voltage is less than 0.10 volt for more than 4 seconds.

P0108

The ECM detects that the MAP sensor voltage is more than 4.90 volts for more than 4 seconds.

Action Taken When the DTC Sets

DTCs P0107 and P0108 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0107 and P0108 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Controls Connector End Views
    •  Engine Control Module Connector End Views

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

    •  Scan Tool Data List
    •  Scan Tool Output Controls
    •  Scan Tool Snapshot Procedure

Special Tools Required

J 35555 Metal Mityvac

Circuit/System Verification

       Important: The MAP sensor 5-volt reference circuit is spliced to other components of the vehicle.

    • If P0641 or P0651 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
    • Verify the integrity of the entire air induction system by inspecting for the following conditions:
       - Any damage to or hairline fractures of, the MAP sensor housing
       - Loose or improper installation
       - Any vacuum leak
    • Verify that restrictions do not exist in the MAP sensor port or vacuum source.
    • Determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter. Compare the parameter to the Altitude vs Barometric Pressure table. Refer to Altitude Versus Barometric Pressure .
    •  Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions.

Circuit/System Testing

    Important: All electrical components and accessories must be turned OFF, and allowed to power down.

  1. Ignition OFF, disconnect the MAP harness connector at the MAP sensor.
  2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
  5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an 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.
  6. Verify the scan tool MAP Sensor parameter is less than 1 kPa.
  7. If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the ECM.
  8. Install a 3-amp fused jumper wire between the signal circuit terminal 1 and the 5-volt reference circuit terminal 3. Verify the scan tool MAP Sensor parameter is greater than 126 kPa.
  9. If less than the specified range, test the signal circuit terminal 1 for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  10. If all circuits test normal, test or replace the MAP sensor.

Component Testing

    Important: You must perform the circuit/system testing, in order to verify the integrity of the MAP sensor circuits, before proceeding with the component testing.

  1. Turn ON the ignition, with the engine OFF, and remove the MAP sensor.
  2. Install a 3-amp fused jumper wire between the 5-volt reference circuit terminal 3 and the corresponding terminal of the MAP sensor.
  3. Install a jumper wire between the low reference circuit terminal 2 of the MAP sensor and ground.
  4. Install a jumper wire at terminal 1 of the MAP sensor.
  5. Connect a DMM between the jumper wire from terminal 1 of the MAP sensor and ground.
  6. Install the J 35555 to the MAP sensor vacuum port. Slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 0-5.2 volts, without any spikes or dropouts.
  7. If the voltage is not within the specified range or is erratic, 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