Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING

Function

The Charge Air Pressure Sensor -G31- / Intake Air Temperature Sensor -G42- is located in the inlet to the intake manifold. The Engine Control Module -J623- uses the sensor's signal to regulate the charge air pressure. There is no substitute function in the event of signal failure. Charge air pressure regulation is shut off, leading to a significant reduction in engine output.

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 Auto. Transmission, ensure Selector Lever position is in "P".
Vehicles with Man. Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
Coolant Temperature: ≥ 80° C.
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 Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING => 2 . -- NO: GATHER more information from customer about the complaint.
2	DISCONNECT: Charge Air Pressure Sensor -G31- harness connector. IGNITION: ON. CHECK: Charge Air Pressure Sensor -G31- harness connector terminals 1 to 3 for voltage. SPECIFIED VALUE: About 5.0 V. IGNITION: OFF. -- Was Value obtained?	-- YES: GO TO: Step 3 Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING => 3 . -- NO: GO TO: Step 4 Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING => 4 .
3	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Charge Air Pressure Sensor -G31- harness connector terminal 2 to the Engine Control Module - J623- harness connector terminal T94 / 30 for resistance. CHECK: Charge Air Pressure Sensor -G31- harness connector terminal 4 to the Engine Control Module - J623- harness connector terminal T94 / 83 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Charge Air Pressure Sensor -G31-. Refer to appropriate repair information. GO TO: Step 5 Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING => 5 . -- NO: 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 Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING => 5 .
4	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Charge Air Pressure Sensor -G31- harness connector terminal 1 to the Engine Control Module - J623- harness connector terminal T94 / 66 for resistance. CHECK: Charge Air Pressure Sensor -G31- harness connector terminal 3 to the Engine Control Module - J623- harness connector terminal T94 / 17 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Engine Control Module -J623-. Refer to appropriate repair information. GO TO: Step 5 Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING => 5 . -- NO: 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 Charge Air Pressure Sensor - G31- / Intake Air Temperature Sensor - G42-, CHECKING => 5 .
5	Final Procedure Perform a road test to verify repair. Do any DTC's return:	-- YES: Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY . Perform the diagnostic procedure for that DTC. -- NO: Repair is complete. Generate readiness code. Refer to READINESS CODE . Return vehicle to Customer.