Engine Temperature Control Module - GX33-, CHECKING

General Description

The Engine Temperature Control Module -GX33- regulates the coolant flow through the cylinder block and heads, engine oil cooler, and the main radiator by means of two mechanically coupled rotary coolant valves. The angular position of the rotary slide valves is regulated according to various engine maps stored in the engine control unit. Various switching positions can be implemented by configuring the rotary slide valves accordingly. This allows rapid heating of the engine, which, in turn, results in lower friction and higher fuel economy.

The Engine Temperature Control Module -GX33- contains the following components:

Engine Temperature Control Actuator -N493-.

The Engine Temperature Control Module -GX33- 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 Engine Temperature Control Module - GX33-, CHECKING - 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Engine Temperature Control Module -GX33- harness connector. IGNITION: ON. CHECK: Engine Temperature Control Module -GX33- harness connector terminals 1 to 3 for voltage. IGNITION: OFF. SPECIFIED VALUE: About 5.0 V. -- Was Value obtained?	-- YES: GO TO: Step 3 Engine Temperature Control Module - GX33-, CHECKING - 3 . -- NO: GO TO: Step 4 Engine Temperature Control Module - GX33-, CHECKING - 4 .
3	REMOVE: Engine Control Module - J623-. Refer to appropriate service information. CHECK: Engine Temperature Control Module -GX33- harness connector terminal 2 to the Engine Control Module - J623- harness connector T105a / 80 for resistance. CHECK: Engine Temperature Control Module -GX33- harness connector terminal 4 to the Engine Control Module - J623- harness connector T105a / 86 for resistance. CHECK: Engine Temperature Control Module -GX33- harness connector terminal 5 to the Engine Control Module - J623- harness connector T105a / 87 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Was Value obtained?	-- YES: REPLACE: Engine Temperature Control Module -GX33-. Refer to appropriate service information. GO TO: Step 5 Engine Temperature Control Module - GX33-, 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 Engine Temperature Control Module - GX33-, CHECKING - 5 .
4	REMOVE: Engine Control Module - J623-. Refer to appropriate service information. CHECK: Engine Temperature Control Module -GX33- harness connector terminal 1 to the Engine Control Module - J623- harness connector T105a / 78 for resistance. CHECK: Engine Temperature Control Module -GX33- harness connector terminal 3 to the Engine Control Module - J623- harness connector T105a / 26 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: GO TO: Step 5 Engine Temperature Control Module - GX33-, 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 Engine Temperature Control Module - GX33-, 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 service 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.