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:

• Mass Airflow Sensor -G70-.
• Intake Air Temperature Sensor -G42-.

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 .

Test Procedure

Step	Procedure	Result / Action to Take
1	PERFORM: Preliminary Check to verify the customers complaint. Refer to PRELIMINARY CHECK . -- Was Complaint verified?	-- YES: GO TO: Step 2 Intake Manifold Sensor - GX9-, CHECKING - 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Intake Manifold Sensor -GX9- harness connector. IGNITION: ON. CHECK: Intake Manifold Sensor -GX9- harness connector terminals 2 to 3 for voltage. IGNITION: OFF. SPECIFIED VALUE: About 5.0 V. -- Was Value obtained?	-- YES: GO TO: Step 3 Intake Manifold Sensor - GX9-, CHECKING - 3 . -- NO: GO TO: Step 4 Intake Manifold Sensor - GX9-, CHECKING - 4 .
3	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Intake Manifold Sensor -GX9- harness connector terminal 1 to the Engine Control Module - J623- harness connector T91 / 10 for resistance. CHECK: Intake Manifold Sensor -GX9- harness connector terminal 4 to the Engine Control Module - J623- harness connector T91 / 29 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Intake Manifold Sensor -GX9-. Refer to appropriate repair information. GO TO: Step 5 Intake Manifold Sensor - GX9-, CHECKING - 5 . -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5 Intake Manifold Sensor - GX9-, CHECKING - 5 .
4	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Intake Manifold Sensor -GX9- harness connector terminal 2 to the Engine Control Module - J623- harness connector T91 / 53 for resistance. CHECK: Intake Manifold Sensor -GX9- harness connector terminal 3 to the Engine Control Module - J623- harness connector T91 / 44 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: GO TO: Step 5 Intake Manifold Sensor - GX9-, CHECKING - 5 . -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5 Intake Manifold Sensor - GX9-, CHECKING - 5 .
5	Final Procedure  Perform a road test to verify repair. -- Does the original DTC return?	-- YES: CHECK: Engine Control Module -J623- harness connector for any damaged, pushed-out pins. REPAIR: As necessary. If all electrical connections are OK: REPLACE: Engine Control Module -J623-. Refer to appropriate repair information. Clear the DTC's. Refer to DIAGNOSTIC MODE 04 -- ERASE DTC MEMORY -->. Repair is complete. Generate Readiness Code. Refer to READINESS CODE . Return vehicle to Customer. -- NO: Perform the diagnostic procedure for any DTC's. If no DTC's return, the repair is complete. Return vehicle to customer.