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 highest 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 lowest manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 10 kPa, when pressures are low, to as much as 103 kPa when pressures are high, depending on the BARO. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

P0107

P0108

P0107

The ECM detects that the MAP sensor voltage is less than 0.1 volt for more than 5 seconds.

P0108

The ECM detects that the MAP sensor voltage is more than 4.8 volts for more than 5 seconds.

DTCs P0107 and P0108 are Type B DTCs.

DTCs P0107 and P0108 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Special Tools Required

J 35555 Metal Mityvac

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

1. If DTC P0641 or P0651 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
2. Verify the integrity of the entire air induction system by inspecting the following conditions:

•	Any damage to, or hairline fractures of, the MAP sensor housing

•	Loose or improper MAP sensor installation

•	Any vacuum leak

3. Verify that restrictions do not exist in the MAP sensor port or vacuum source.
4. Determine the current vehicle testing altitude.
5. 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 .
6. Use the scan tool and compare the MAP Sensor parameter to a known good vehicle under various operating conditions.
7. Engine running, observe the DTC information with a scan tool. DTCs P0107 or P0108 should not set.
8. 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.

1. Ignition OFF, disconnect the harness connector at the MAP sensor.
2. Ignition OFF, allow at least 60 seconds for the control module to power down.
3. Test for less than 5 ohms of resistance between the low reference circuit terminal A and ground.

⇒	If greater than the specified value, 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.

⇒	If less than 4.8 volts, 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 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. Verify the scan tool MAP Sensor parameter is less than 12 kPa.

⇒	If greater than 12 kPa, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM.

6. 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 103 kPa.

⇒	If less than 103 kPa, test the signal circuit terminal B for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

7. If all circuits test normal, test the MAP sensor. Refer to Component Testing for instructions.

Important: You must perform the Circuit/System Testing before proceeding with the Component Testing.

1. Ignition ON, remove the MAP sensor.
2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and a corresponding terminal 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. Install a 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 0-5.2 volts without any spikes or dropouts.

⇒	If the voltage is not within the specified range or is erratic, replace the MAP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.