Intake Air Temperature Sensor - G42-, Checking

General Description

The Engine Control Module -J623- uses the Intake Air Temperature Sensor -G42- signal to calculate a correction value for the charge air pressure. Evaluation of the signal gives consideration to the influence of temperature on the density of the charge air.

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 Air Temperature Sensor - G42-, CHECKING => 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Intake Air Temperature Sensor -G42- harness connector. CHECK: Intake Air Temperature Sensor -G42- component connector terminals 1 to 2 for resistance. SPECIFIED VALUE: 1, 800 Ω (+/- 750 Ω @ approx. 20° C). -- Was Value obtained?	-- YES: GO TO: Step 3 Intake Air Temperature Sensor - G42-, CHECKING => 3 . -- NO: REPLACE: Intake Air Temperature Sensor -G42-. Refer to appropriate repair information. GO TO: Step 4 Intake Air Temperature Sensor - G42-, CHECKING => 4 .
3	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Intake Air Temperature Sensor -G42- harness connector terminal 1 to the Engine Control Module - J623- harness connector T60 / 42 for resistance. CHECK: Intake Air Temperature Sensor -G42- harness connector terminal 2 to the Engine Control Module - J623- harness connector T60 / 14 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: TIP: The Intake Air Temperature Sensor -G42- may fail under loaded operation; please swap a known good Intake Air Temperature Sensor -G42- prior to continuing to the next step. GO TO: Step 4 Intake Air Temperature Sensor - G42-, CHECKING => 4 . -- 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 4 Intake Air Temperature Sensor - G42-, CHECKING => 4 .
4	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.