Engine Coolant Temperature Sensor On Engine - G82-, Checking

General Description

The Engine Coolant Temperature Sensor On Engine -G82- sends information about the current coolant temperature to the Engine Control Module -J623-. It uses the coolant temperature as a correction value for calculating the injection quantity.

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: .
View clean working conditions: .

Test Procedure

NOTE:

Note the CA1 and CMC both use the ECM connector T105a, and the CA2 uses the ECM connector T105b. Both connectors are identical except for the suffix of "a" or "b". For simplicity, please use the suffix "a".

Step	Procedure	Result / Action to Take
1	PERFORM: Preliminary Check to verify the customers complaint. Refer to . -- Was Complaint verified?	-- YES: GO TO: Step 2 Engine Coolant Temperature Sensor On Engine - G82-, CHECKING - 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Engine Coolant Temperature Sensor On Engine -G82- harness connector. CHECK: Engine Coolant Temperature Sensor On Engine -G82- component connector terminals 1 to 2 for resistance. IGNITION: OFF. SPECIFIED VALUE: 2, 250 Ω (+/- 750 Ω @ approx. 20° C). -- Was Value obtained?	-- YES: GO TO: Step 3 Engine Coolant Temperature Sensor On Engine - G82-, CHECKING - 3 . -- NO: REPLACE: Engine Coolant Temperature Sensor On Engine -G82-. Refer to appropriate Service Information. GO TO: Step 4 Engine Coolant Temperature Sensor On Engine - G82-, CHECKING - 4 .
3	REMOVE: Engine Control Module - J623-. Refer to appropriate Service Information. CHECK: Engine Coolant Temperature Sensor On Engine -G82- harness connector terminal 1 to the Engine Control Module - J623- harness connector T105a / 11 for resistance. CHECK: Engine Coolant Temperature Sensor On Engine -G82- harness connector terminal 2 to the Engine Control Module - J623- harness connector T105a / 57 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: TIP: The Engine Coolant Temperature Sensor On Engine -G82- may fail under loaded operation; please swap a known good Engine Coolant Temperature Sensor On Engine -G82- prior to continuing to the next step. GO TO: Step 4 Engine Coolant Temperature Sensor On Engine - G82-, 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 Engine Coolant Temperature Sensor On Engine - G82-, 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 Service Information. Clear the DTC's. Refer to . Repair is complete. Generate Readiness Code. Refer to . 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.