Intake Manifold Sensor - GX9-, Checking: General Description

The air mass and charge pressure are two factors used for engine load management. For this purpose, there are several sensors with absolutely identical functions. They measure the intake air temperature and the intake manifold pressure. The first sender unit is located upstream of the Throttle Valve Control Module -J338/GX3- in the Intake Manifold Sensor -GX9-. They measure the pressure and temperature of the air in each individual cylinder bank. The values measured here correspond to the actual air mass in the cylinder bank(s).

The Intake Manifold Sensor -GX9- contains the following components:

• Intake Air Temperature Sensor -G42-.
• Manifold Absolute Pressure Sensor -G71-.

The Intake Manifold Sensor -GX9- components cannot be serviced separately, and they must be serviced as a unit.

Special tools and workshop equipment required 

• Multimeter.
• Wiring Diagram.
• Scan Tool.

Test requirements 

• Fuses OK.
• Battery voltage OK.
• Switch OFF all electrical and electronic accessories.
• Vehicles with automatic transmission, ensure the selector lever position is in "P".
• Vehicles with manual transmission, ensure the shifter lever position is in "N" with the parking brake applied.
• Observe all safety precautions: SAFETY PRECAUTIONS .
• View clean working conditions: CLEAN WORKING CONDITIONS .