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 Voltage

P0107, P0698, P2564

P0106

P0107

P0106, P0401, P0699, P2565

P0106

MAP Sensor Signal

P0107

P0106

P0107

P0108

P0106

Low Reference

--

P0106

P0108

--

P0106

Typical Scan Tool Data

MAP Sensor

Circuit

Short to Ground

Open

Short to Voltage

Parameter Normal Range: Ignition ON. BARO

5-Volt Reference

43 kPa

43 kPa

200-205 kPa

MAP Sensor Signal

43 kPa

43 kPa

255 kPa

Low Reference

--

255 kPa

--

Circuit/System Description

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by turbocharger output, engine speed, accelerator pedal input, 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 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 lowest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the vehicle is operating at idle or when the ignition is ON, while the engine is OFF. The ECM uses the MAP sensor to aid in diagnosis of the turbocharger performance. The highest manifold pressures occur when the turbocharger output is high. Manifold pressure can range from 58 kPa (8 psi) when pressure are low, to more than 240 kPa (34 psi) when pressures are high, depending on the BARO. The MAP sensor has a range of 33-255 kPa (4-36 psi).

Conditions for Running the DTC

    • The engine is running for more than 1 second.
    • The engine speed is between 500-2,500 RPM.
    • The ignition 1 voltage is more than 11 volts.
    • The above conditions are met for more than 2 second.
    • DTC P0107 and P0108 run continuously within the enabling conditions.

Conditions for Setting the DTC

P0107

The MAP voltage is less than 0.15 volt for 2 seconds.

P0108

The ECM detects that the MAP voltage is more than 4.1 volts for more than 2 seconds.

Action Taken When the DTC Sets

    • DTC P0107 and P0108 are type A DTCs.
    • The control module commands Reduced Engine Power mode.
    • A message center or an indicator may display Reduced Engine Power.

Conditions for Clearing the MIL/DTC

DTCs P0107 and P0108 are type A DTCs.

Diagnostic Aids

Verify that any electrical aftermarket devices are properly connected and grounded. Refer to Checking Aftermarket Accessories .

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Controls Connector End Views
    •  Engine Controls Component 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
    •  Diagnostic Trouble Code (DTC) Types

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification

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

  1. If DTCs P003A, P0045, P0234, P0698, P0699, or P2563 are set, diagnose those codes first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further information.
  2. Verify the integrity of the entire air induction system by inspecting for the following conditions:
  3. • Damaged components
    • Loose or improper installation
    • Any vacuum leak
    • Verify that restrictions do not exist in the MAP sensor port or vacuum source.
  4. 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 .
  5. Ignition ON, engine OFF, observe the scan tool MAP Sensor parameter. The MAP Sensor parameters should match the BARO Sensor parameter.
  6. Engine running, observe the DTC information with a scan tool. DTCs P0107 or P0108 should not set.
  7. 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 data.

Circuit/System Testing

Important: Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

  1. Ignition OFF, disconnect the harness connector at the MAP sensor.
  2. Ignition OFF, allow at least 60 seconds for the ECM to power down. Test for less than 5 ohms of resistance between the low reference circuit terminal A and a good 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 C 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.
  6. Verify the scan tool MAP Sensor parameter is less than 45 kPa.
  7. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM.
  8. 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 250 kPa.
  9. If less than the specified range, test the sensor signal circuit 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 the MAP sensor. Refer to Component Testing for instructions.

Component Testing

Dynamic Test

  1. Ignition OFF, disconnect and remove the MAP sensor.
  2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and the terminal C of the MAP sensor.
  3. Install a jumper wire between the low reference terminal A and ground at the MAP sensor.
  4. Install a jumper wire at the signal terminal B of the MAP sensor.
  5. Connect a DMM between the jumper wire from terminal B of the MAP sensor and ground.
  6. Ignition ON, install the J 35555 to the MAP sensor vacuum port. Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 4.9-0.04 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