Engine Cooling System (2ZR-FE): Overview Toyota Corolla X

DESCRIPTION

The ECM calculates an appropriate cooling fan speed based on the engine coolant temperature, air conditioning switch condition, refrigerant pressure, engine speed, and vehicle speed and sends the signals to the cooling fan ECU to regulate the cooling fan. The cooling fan ECU controls the cooling fan speed based on the duty ratio signal sent from the ECM. By basing its control on the operating conditions, the ECM can control the fan speed optimally using the cooling fan ECU, achieving both high cooling performance and quietness. The cooling fan speed is determined based on the engine coolant temperature, air conditioner operating conditions, engine speed, and vehicle speed.

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1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL COOLING FAN) Connect the Techstream to the DLC3. Turn the ignition switch to ON. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan. Check the operation of the cooling fan using the Techstream. OK ACTIVE TEST REFERENCE Tester Operation Fan Operation ON Cooling fan operates OFF Cooling fan stopped Result RESULT REFERENCE Result Proceed to OK A NG (Cooling fan does not operate) B NG (Cooling fan does not stop) C B: Go to step 2 C: Go to step 14 A: PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN PROBLEM SYMPTOMS TABLE (See «SYSTEM DIAGRAM»(ref-338653-S35619311102009082800000) )
2. INSPECT COOLING FAN ECU Disconnect the ECM connector. Turn the ignition switch to ON. Check the operation of the cooling fan. OK: The cooling fan operates. Reconnect the ECM connector. NG: Go to step 3 OK: REPLACE ECM (See «REMOVAL»(/toyota/corolla/x-2006-2010/remont/testing-diagnostics/#engine-control-system-2zr-fe) )
3. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU) Disconnect the cooling fan ECU connector. Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A50-43 (RFC) - A41-2 (SI) Always Below 1 ohms Standard Resistance (Check for Short) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A50-43 (RFC) or A41-2 (SI) - Body ground Always 10 kohms or higher Reconnect the ECM connector. Reconnect the cooling fan ECU connector. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - COOLING FAN ECU) OK: Go to next step
4. INSPECT COOLING FAN MOTOR Disconnect the cooling fan ECU connector. Connect a battery positive (+) lead to terminal 2 of the cooling fan motor connector, and connect a battery negative (-) lead to terminal 1 of the cooling fan motor connector. Check the cooling fan motor. OK: The cooling fan operates. Reconnect the cooling fan ECU connector. NG: REPLACE COOLING FAN MOTOR (See «REMOVAL»(ref-338653-S17490041952009082800000) ) OK: Go to next step
5. CHECK COOLING FAN ECU (POWER SOURCE) Disconnect the cooling fan ECU connector. Turn the ignition switch to ON. Measure the voltage according to the value(s) in the table below. Standard Voltage STANDARD VOLTAGE SPECIFICATION Tester Connection Switch Condition Specified Condition A41-1 (+B1) - A41-3 (E1) Ignition switch ON 11 to 14 V Reconnect the cooling fan ECU connector. NG: Go to step 6 OK: REPLACE COOLING FAN ECU (See «PARTS LOCATION»(ref-338653-S33424996472009082800000) )
6. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - BODY GROUND) Disconnect the cooling fan ECU connector. Measure the resistance according to the value(s) in the table below. Standard Resistance STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A41-3 (E1) - Body ground Always Below 1 ohms Reconnect the cooling fan ECU connector. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU - BODY GROUND) OK: Go to next step
7. INSPECT FAN NO. 1 RELAY Remove the FAN No. 1 relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 3 - 5 Normal 10 kohms or higher 3-5 Apply battery voltage between terminals 1 and 2 Below 1 ohms Reinstall the FAN No. 1 relay. NG: REPLACE FAN NO. 1 RELAY OK: Go to next step
8. INSPECT FUSIBLE LINK BLOCK (RDI FAN FUSE) Check the RDI FAN fuse. NG: REPLACE FUSIBLE LINK BLOCK OK: Go to next step
9. INSPECT FUSE (ECU-IG NO. 1) Remove the ECU-IG No. 1 fuse from the instrument panel junction block. Measure the resistance according to the value(s) in the table below. Standard Resistance STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition ECU-IG No. 1 fuse Always Below 1 ohms Reinstall the ECU-IG No. 1 fuse. NG: REPLACE FUSE (ECU-IG NO. 1 FUSE) OK: Go to next step
10. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - FAN NO. 1 RELAY) Disconnect the cooling fan ECU connector. Remove the FAN No. 1 relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A41-1 (+B1) - 5 (FAN No. 1 relay) Always Below 1 ohms Standard Resistance (Check for Short) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A41-1 (+B1) or 5 (FAN No. 1 relay) - Body ground Always 10 kohms or higher Reconnect the cooling fan ECU connector. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU - FAN NO. 1 RELAY) OK: Go to next step
11. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - BODY GROUND) Remove the FAN No. 1 relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 2 (FAN No. 1 relay) - Body ground Always Below 1 ohms Reinstall the FAN No. 1 relay. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - BODY GROUND) OK: Go to next step
12. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - ECU-IG NO. 1 FUSE) Remove the ECU-IG No. 1 fuse from the instrument panel junction block. Remove the FAN No. 1 relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 2 (ECU-IG No. 1 fuse) - 1 (FAN No. 1 relay) Always Below 1 ohms Standard Resistance (Check for Short) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 2 (ECU-IG No. 1 fuse) or 1 (FAN No. 1 relay) - Body ground Always 10 kohms or higher Reinstall the ECU-IG No. 1 fuse. Reinstall the FAN No. 1 relay. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - ECU-IG NO. 1 FUSE) OK: Go to next step
13. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - RDI FAN FUSE) Remove the fusible link block assembly from the engine room relay block. Disconnect the fusible link block connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 3 (FAN No. 1 relay) - 1 C-2 (Fusible link block) Always Below 1 ohms Standard Resistance (Check for Short) STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 3 (FAN No. 1 relay) or 1C-2 (Fusible link block) - Body ground Always 10 kohms or higher Reconnect the fusible link block connector. Reinstall the fusible link block assembly. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - RDI FAN FUSE) OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - RDI FAN FUSE)
14. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU) Disconnect the cooling fan ECU connector. Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard Resistance STANDARD RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A50-43 (RFC) - A41-2 (SI) Always Below 1 ohms Reconnect the ECM connector. Reconnect the cooling fan ECU connector. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - COOLING FAN ECU) OK: REPLACE COOLING FAN ECU (See «PARTS LOCATION»(ref-338653-S33424996472009082800000) )

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1. DRAIN ENGINE COOLANT Loosen the lower radiator drain cock plug. CAUTION: Do not loosen the lower radiator drain cock plug while the engine and radiator are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns. HINT: Collect the coolant in a container and dispose of it according to the regulations in your area. Remove the radiator cap. Loosen the cylinder block drain cock plug. HINT: The plug is on the backside of the generator on the exhaust manifold side.
2. ADD ENGINE COOLANT Tighten the lower radiator drain cock plug. Tighten the cylinder block drain cock plug. Torque: 13 N*m (130 kgf*cm, 9 ft.*lbf) Loosen the upper radiator drain cock plug. Slowly fill the radiator with TOYOTA Super Long Life Coolant (SLLC). Standard Capacity ENGINE COOLANT CAPACITY SPECIFICATION Item Capacity Engine coolant 5.5 liters (5.8 US qts, 4.8 lmp. qts) HINT: TOYOTA vehicles are filled with TOYOTA SLLC at the factory. In order to avoid damage to the engine cooling system and other technical problems, only use TOYOTA SLLC or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, non-borate coolant with long-life hybrid organic acid technology (coolant with long-life hybrid organic acid technology consists of a combination of low phosphates and organic acids). Contact your TOYOTA dealer for further details. NOTE: Never use water as a substitute for engine coolant. Squeeze the inlet and outlet radiator hoses several times by hand, and then check the level of the coolant. If the coolant level is low, add coolant. Tighten the upper radiator drain cock plug. Slowly pour coolant into the radiator reservoir tank until it reaches the FULL line. Install the radiator cap sub-assembly and reservoir tank cap. Start the engine and warm it up. Bleed air from the cooling system. NOTE: Before starting the engine, turn the A/C switch off. Adjust the air conditioning temperature setting to MAX (HOT). Adjust the air conditioning blower setting to LO. Warm up the engine until the thermostat opens. While the thermostat is open, allow the coolant to circulate for several minutes. HINT: Thermostat opening timing can be determined by squeezing the inlet radiator hose, and sensing vibrations when the engine coolant starts to flow inside the hose. CAUTION: When squeezing the radiator hoses: Wear protective gloves. Be careful as the radiator hoses are hot. Keep your hands away from the radiator fan. Stop the engine, and wait until the engine coolant cools down. Add engine coolant to the FULL line on the radiator reservoir.
3. INSPECT FOR COOLANT LEAK (See «ON-VEHICLE INSPECTION»(ref-338653-S06605721272009082800000) )

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1. REMOVE NO. 2 CYLINDER HEAD COVER (See «REMOVAL»(ref-338644-S00228041112009082800000) )
2. REMOVE ENGINE UNDER COVER RH
3. REMOVE V-RIBBED BELT (See «REMOVAL»(ref-338644-S41220295392009082800000) )
4. INSPECT WATER PUMP ASSEMBLY Turn the pulley and check that the water pump bearing moves smoothly and quietly. If necessary, replace the water pump assembly. Make sure that there are no drops of coolant on the water pump housing. If necessary, replace the water pump assembly.
5. INSTALL V-RIBBED BELT (See «INSTALLATION»(ref-338644-S16072683972009082800000) )
6. ADJUST V-RIBBED BELT (See «INSTALLATION»(ref-338644-S16072683972009082800000) )
7. INSPECT V-RIBBED BELT (See «ON-VEHICLE INSPECTION»(ref-338644-S13552867762009082800000) )
8. INSTALL ENGINE UNDER COVER RH
9. INSTALL NO. 2 CYLINDER HEAD COVER (See «INSTALLATION»(ref-338644-S27795634972009082800000) )

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1. REMOVE NO. 2 CYLINDER HEAD COVER (See «REMOVAL»(ref-338644-S00228041112009082800000) )
2. REMOVE ENGINE UNDER COVER RH
3. DRAIN ENGINE COOLANT (See «REPLACEMENT»(ref-338653-S35958268042009082800000) )
4. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
5. REMOVE V-RIBBED BELT (See «REMOVAL»(ref-338644-S41220295392009082800000) )
6. REMOVE GENERATOR ASSEMBLY (See «REMOVAL»(ref-338660-S16415907682009082800000) )
7. REMOVE WATER PUMP ASSEMBLY Remove the 5 bolts and water pump assembly from the timing chain cover. Remove the water pump gasket from the timing chain cover.

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1. INSTALL WATER PUMP ASSEMBLY Align the protrusion of a new water pump gasket with the cutout in the timing chain cover and install the gasket to the groove of the timing chain cover. HINT: Be sure to clean the contact surfaces. Install the water pump assembly to the timing chain cover with the 5 bolts. Torque: Bolt A 26 N*m (260 kgf*cm, 19 ft.*lbf) Bolt B 24 N*m (245 kgf*cm, 18 ft.*lbf) Bolt Length BOLT LENGTH REFERENCE Item Length Bolt A 35 mm (1.38 In.) Bolt B 18 mm (0.709 In.)
2. INSTALL GENERATOR ASSEMBLY (See «INSTALLATION»(ref-338660-S25609767852009082800000) )
3. INSTALL V-RIBBED BELT (See «INSTALLATION»(ref-338644-S16072683972009082800000) )
4. ADJUST V-RIBBED BELT (See «INSTALLATION»(ref-338644-S16072683972009082800000) )
5. INSPECT V-RIBBED BELT (See «ON-VEHICLE INSPECTION»(ref-338644-S13552867762009082800000) )
6. CONNECT CABLE TO NEGATIVE BATTERY TERMINAL (See «INSTALLATION»(/toyota/corolla/x-2006-2010/remont/fuel-system/#engine-fuel-system-2zr-fe) )
7. ADD ENGINE COOLANT (See «REPLACEMENT»(ref-338653-S35958268042009082800000) )
8. INSPECT FOR COOLANT LEAK (See «ON-VEHICLE INSPECTION»(ref-338653-S06605721272009082800000) )
9. INSTALL ENGINE UNDER COVER RH
10. INSTALL NO. 2 CYLINDER HEAD COVER (See «INSTALLATION»(ref-338644-S27795634972009082800000) )

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1. DRAIN ENGINE COOLANT (See «REPLACEMENT»(ref-338653-S35958268042009082800000) )
2. REMOVE WATER INLET Remove the 2 nuts and water inlet.
3. REMOVE THERMOSTAT Remove the thermostat. Remove the gasket from the thermostat.

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1. INSPECT THERMOSTAT HINT: The valve opening temperature is inscribed on the thermostat. Immerse the thermostat in water and then gradually heat the water. Check the valve opening temperature of the thermostat. Standard valve opening temperature: 80 to 84°C (176 to 183°F) HINT: If the valve opening temperature is not as specified, replace the thermostat. Check the valve lift. Standard valve lift: 10 mm (0.39 in.) or more at 95°C (203°F) HINT: If the valve lift is not as specified, replace the thermostat. Check that the valve is fully closed when the thermostat is at low temperatures (below 77°C (171°F)). HINT: If it is not fully closed, replace the thermostat.

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1. INSTALL THERMOSTAT Install a new gasket on the thermostat. Install the thermostat to the water inlet with the jiggle valve upward. HINT: The jiggle valve may be set to within 10° on either side of the indicated position.
2. INSTALL WATER INLET Install the water inlet with the 2 nuts. Torque: 10 N*m (102 kgf*cm, 7 ft.*lbf)
3. ADD ENGINE COOLANT (See «REPLACEMENT»(ref-338653-S35958268042009082800000) )
4. INSPECT FOR COOLANT LEAK (See «ON-VEHICLE INSPECTION»(ref-338653-S06605721272009082800000) )

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1. INSPECT COOLING FAN MOTOR Check that the motor operates smoothly when the battery is connected to the cooling fan motor connector. If the motor does not operate smoothly, replace the cooling fan motor. Connect the pickup of a clamp-on ammeter over one of the two wires for the cooling fan motor. Measure the current while the motor is operating. Standard Current STANDARD CURRENT REFERENCE Connection Condition Specified Condition Fan wire 20°C (68°F) 7.4 to 10.9 A If the result is not as specified, replace the cooling fan motor.

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1. REMOVE RADIATOR ASSEMBLY HINT: See «REMOVAL»(ref-338653-S29348571072009082800000)
2. REMOVE FAN Remove the nut, then remove the fan.
3. REMOVE COOLING FAN MOTOR Disconnect the connector and 2 clamps from the fan shroud. Remove the 3 screws, then remove the cooling fan motor.

See also:
• INSPECTION
• INSTALLATION