Engine Temperature Control Actuator - N493-, CHECKING

General Description

The coolant flow is regulated by means of two mechanically coupled rotary slide 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.

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 concern. Refer to PRELIMINARY CHECK . -- Was Complaint verified?	-- YES: GO TO: Step 2 Engine Temperature Control Actuator - N493-, CHECKING - 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: ON. CHECK: Engine Temperature Control Actuator -N493- harness connector terminals 1 to 3 for voltage. SPECIFIED VALUE: About 5.0 V. IGNITION: OFF. -- Was Value obtained?	-- YES: GO TO: Step 3 Engine Temperature Control Actuator - N493-, CHECKING - 3 . -- NO: GO TO: Step 4 Engine Temperature Control Actuator - N493-, CHECKING - 4 .
3	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Engine Temperature Control Actuator -N493- harness connector terminal 2 to the Engine Control Module - J623- harness connector T105 / 80 for resistance. CHECK: Engine Temperature Control Actuator -N493- harness connector terminal 4 to the Engine Control Module - J623- harness connector T105 / 86 for resistance. CHECK: Engine Temperature Control Actuator -N493- harness connector terminal 5 to the Engine Control Module - J623- harness connector T105 / 87 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Engine Temperature Control Actuator -N493-. Refer to appropriate repair information. GO TO: Step 5 Engine Temperature Control Actuator - N493-, 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 Actuator - N493-, CHECKING - 5 .
4	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. For all TT and A3 to Oct 2015 vehicles: CHECK: Engine Temperature Control Actuator -N493- harness connector terminal 1 to the Engine Control Module - J623- harness connector T105 / 33 for resistance. For all TT and A3 to Oct 2015 vehicles: CHECK: Engine Temperature Control Actuator -N493- harness connector terminal 3 to the Engine Control Module - J623- harness connector T105 / 35 for resistance. For A3 from Nov 2015 vehicles: CHECK: Engine Temperature Control Actuator -N493- harness connector terminal 1 to the Engine Control Module - J623- harness connector T105 / 78 for resistance. For A3 from Nov 2015 vehicles: CHECK: Engine Temperature Control Actuator -N493- harness connector terminal 3 to the Engine Control Module - J623- harness connector T105 / 26 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: GO TO: Step 5 Engine Temperature Control Actuator - N493-, 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 Actuator - N493-, 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.