Engine Cooling System Chevrolet Malibu VII

Fastener Tightening Specifications

Adhesives, Fluids, Lubricants, and Sealers

Scheme 1

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) commands the fans ON in high speed or low speed. In low speed, the fans are configured in series. In high speed, the fans are configured in parallel.

In low speed operation, the ECM applies ground to the coil side of the low speed relay, which is COOL/FAN 1 relay 28. Voltage is applied directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to the left fan through the de-energized series/parallel relay, which is the COOL/FAN SER/PAR relay 29, so that both fans operate at low speed.

In high speed operation, the ECM applies a ground to the coil side of the low speed relay, the series/parallel relay, and the high speed relay, which is COOL/FAN 2 relay 30. Voltage is applied directly to the right cooling fan through the switch side of the high speed relay. The left cooling fan obtains voltage through the low speed relay and ground through the series/parallel relay.

When the ECM is commanding a fan relay ON, the voltage of the control circuit should be low, near 0 volts. When the ECM is commanding a fan relay OFF, the voltage of the control circuit should be high, near battery voltage. If the ECM detects that the actual voltage of the relay control circuit is different than the expected voltage, DTC P0480 or P0481 will set and the affected ECM driver will be disabled.

Conditions for Running the DTC

1. The engine is running.
2. The system voltage is between 11-18 volts.
3. The relay control circuit is transitioned from OFF to ON, or ON to OFF.

Conditions for Setting the DTC

1. An improper voltage level has been detected on the cooling fan relay control circuit.
2. The condition must be present for a minimum of 30 seconds.

Action Taken When the DTC Sets

DTCs P0480 and P0481 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0480 and P0481 are Type B DTCs.

Reference Information

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

1. «Component Connector End Views»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)
2. «Electrical Center Identification Views»(/chevrolet/malibu/vii-2008-2012/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-electrical-center-identification-views)

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Wiring Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify cooling fan operation using the scan tool commands listed below

1. Fan Relay 1 ON-Both fans run at low speed.
2. Fan Relays 2 and 3 ON-The right fan runs at high speed, the left fan is OFF.
3. Fan Relays 1, 2 and 3 ON-Both fans run at high speed.

Circuit/System Testing

1. Ignition OFF, disconnect the 3 cooling fan relays listed below. COOL/FAN 1 COOL/FAN SER/PAR COOL/FAN 2
2. Ignition ON, verify that a test lamp illuminates between ground and the appropriate battery voltage circuit terminal listed below: Cool Fan 1 relay, terminal 86 Cool Fan 2 relay, terminal 86 COOL/FAN SER/PAR relay, terminal 85 If the test lamp does not illuminate, test the battery voltage circuit for a short to ground or an open/high resistance.
3. Verify that a test lamp does not illuminate between terminal 85 and terminal 86 of each relay listed below: COOL/FAN 1 COOL/FAN 2 If the test lamp illuminates, test the control circuit for a short to ground. If the circuit test normal, replace the ECM.
4. Remove the test lamp.
5. Ignition ON, command the affected relay ON using a scan tool. Verify the affected scan tool FC Relay Control Ckt. Short Volts Test Status Parameter is OK. For the COOL/FAN 1 relay, use the scan tool Fan Relay 1 command. For the COOL/FAN SER/PAR and COOL/FAN 2 relays, use the scan tool Relay 2 and 3 command. If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
6. Install a 3A fused jumper wire between terminal 86 and terminal 85. Command the affected relay ON with a scan tool. Verify the scan tool Relay Control Ckt Short Volts Test Status Parameter is Fault. If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
7. If all circuits and the ECM test normal, replace the affected relay.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Underhood Electrical Center or Junction Block Replacement»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
3. «Cooling Fan and Shroud Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)
4. «Control Module References»(/chevrolet/malibu/vii-2008-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) uses the engine coolant temperature (ECT) sensor to monitor the engine for an over-temperature condition. This condition occurs when the coolant temperature is above a calibrated value. The ECM will alternately disable 2 groups of cylinders by turning OFF the fuel injectors. By switching between the 2 groups of cylinders, the ECM is able to reduce the temperature of the coolant.

1. The engine is running.
2. DTC P0116, P0117, P0118, or P0128 are not set.

The coolant temperature is more than 131°C (267.8°F) for more than 7 seconds.

1. DTC P1258 is a Type A DTC.
2. The engine will operate in the Overheated Engine Protection Operating Mode.
3. The IP will illuminate the coolant temperature indicator lamp and the driver information center (DIC), if equipped, may display a message.

Conditions for Clearing the DTC

DTC P1258 is a Type A DTC.

Description and Operation

1. «Cooling Fan Description and Operation»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Instrument Cluster Description and Operation»(/chevrolet/malibu/vii-2008-2012/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges)
3. «Indicator/Warning Message Description and Operation»(/chevrolet/malibu/vii-2008-2012/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges__indicatorwarning-message-description-and-operation)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If DTC P0480 or P0481 are set, diagnose those DTCs first.
2. Observe the engine coolant level. The engine coolant level should be within the operating range. Refer to Capacities - Approximate Fluid, and Engine Coolant in the Owner's Manual.
3. Ensure that the vehicle has the correct engine coolant with correct concentration and is not old, contaminated, or contains additives. Refer to Recommended Fluids and Lubricants in the Owner's Manual.
4. Inspect the cooling system for the following: Leaks Kinked or pinched hoses, especially at the radiator Loose, missing, or damaged radiator air seals or deflectors Air flow obstructions or bent fins at the radiator or the A/C condenser-Refer to «Symptoms - Engine Cooling (2.4L)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Command the cooling fans ON and OFF, low and high speed. The engine cooling fans should turn ON and OFF with each command. If the cooling fans do not function as indicated, refer to «Cooling Fan Inoperative»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Test the thermostat for correct operation. Refer to «Thermostat Diagnosis»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) .
2. Test the engine cooling system for overheating. Refer to «Engine Overheating»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating) .
3. Inspect the water pump and coolant flow for correct operation. Refer to «Water Pump Cleaning and Inspection»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-2-of-3__water-pump-cleaning-and-inspection) for the 3.5L engine or «Water Pump Cleaning and Inspection»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-off-vehicle-2-of-3) for the 3.6L engine.
4. Inspect the engine mechanical for worn/leaking/cracked cylinder heads or engine block. Refer to «Coolant in Combustion Chamber»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-diagnostic-information-and-procedures__coolant-in-combustion-chamber) for the 3.5L engine or «Coolant in Combustion Chamber»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-diagnostic-information-and-procedures__coolant-in-combustion-chamber) for the 3.6L engine. Also refer to «Coolant in Engine Oil»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-diagnostic-information-and-procedures__coolant-in-engine-oil) for the 3.5L engine or «Coolant in Engine Oil»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-diagnostic-information-and-procedures__coolant-in-engine-oil) for the 3.6L engine.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Important Preliminary Inspections Before Starting

Before using the Symptom diagnosis, perform the following

1. Perform «Diagnostic System Check - Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) and verify all of the following items: Ensure that the engine control module (ECM) and indicator lamp are operating correctly. Ensure that there are no diagnostic trouble codes (DTCs) that are stored. Scan tool data is within a normal operating range. Refer to «Control Module References»(/chevrolet/malibu/vii-2008-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for scan tool information.
2. Verify the customer concern.
3. Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.
4. Locate the correct symptom. Perform the tests and inspections associated with the symptom.

Review the system operation in order to familiarize yourself with the system functions. Refer to Cooling Fan Description and Operation .

Visual/Physical Inspection

Several of the symptom procedures call for a careful visual and physical inspection. This can lead to correcting a condition without further tests and can save time. This inspection should include the following areas

1. Ensure that the control module grounds are clean, tight, and correctly located.
2. Inspect cooling system hoses and pipes for splits, kinks, and proper connections. Inspect thoroughly for any type of a leak or a restriction.
3. Inspect for a dirty or restricted radiator and HVAC condenser.
4. Inspect for aftermarket devices which could affect the operation of the Cooling System.
5. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
6. Inspect the surge tank reservoir for the proper coolant level.

Identifying Intermittent Conditions

Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movement of a component. Refer to the following for a list to help determine an intermittent condition

1. Moisture and water intrusion in connectors, terminals, and components
2. Connector mating
3. Terminal contact
4. High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
5. Harness that is located too tight, or chaffed circuits
6. High or low ambient temperature
7. High or low engine coolant temperatures
8. High underhood temperatures
9. Heat build up in component or circuit due to circuit resistance, poor terminal contact, or high electrical load
10. High or low system voltage
11. High vehicle load conditions
12. Rough road surface
13. Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
14. Incorrect installation of non-factory, aftermarket, and after factory add on accessories

If an intermittent is determined, refer to Testing for Intermittent Conditions and Poor Connections for specific strategies in diagnosing intermittent conditions.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Cooling Fan Always On»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Cooling Fan Inoperative»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)
3. «Engine Overheating»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating)
4. «Loss of Coolant»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant)
5. «Thermostat Diagnosis»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis)
6. «Engine Fails To Reach Normal Operating Temperature»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__engine-fails-to-reach-normal-operating)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) commands the fans ON in either high speed or low speed, depending on cooling requirements. In low speed, both fans are turned ON at a reduced speed. High speed has both fans turned ON at full speed.

In low speed operation, the ECM applies ground to the coil side of the low speed fan relays, which is COOL/FAN 1 relay 28. This energizes the coil and applies voltage directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to the left fan through the de-energized series/parallel relay, which is COOL/FAN SER/PAR relay 29 so that both operate at low speed.

In high speed operation, the ECM applies a ground to the coil side of the low speed relay, the series/parallel relay, and the high speed fan relay, which is COOL/FAN 2 relay 30. On the high speed relay, the energized coil closes the switch side of the relay and applies voltage directly to the right cooling fan through the switch side of the relay. At the same time, the ECM energizes the series/parallel relay pulling the switch side over, providing a direct path to ground for the left cooling fan, which has voltage applied through the energized low speed relay. In high speed mode, the fans are operated as a parallel circuit with full voltage applied to each.

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Wiring Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

1. If DTCs P0480 or P0481 are set, perform those diagnostics first.
2. Ignition ON, verify with a scan tool that the control module is not commanding fan activation.
3. Ignition ON, observe that the fans are not activated.

1. Ignition OFF, disconnect the high speed fan relay, which is COOL/FAN 2 relay 30.
2. Ignition ON, observe that both fans are now OFF. If both fans are OFF, replace the high speed relay. If either fan is still activated, remove the low speed fan relay, which is COOL/FAN 1 relay 28. If both fans are now OFF, replace the low speed relay. If either fan is still activated, test for a short to voltage in the fan voltage supply circuit.

1. «Underhood Electrical Center or Junction Block Replacement»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
3. «Cooling Fan and Shroud Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)
4. «Control Module References»(/chevrolet/malibu/vii-2008-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Repair Verification

1. Ignition ON, verify with a scan tool that the control module is not commanding fan activation.
2. Ignition ON, observe that the fans are not activated.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) commands the fans ON in either high speed or low speed, depending on cooling requirements. In low speed, both fans are turned ON at a reduced speed. High speed has both fans turned ON at full speed.

In low speed operation, the ECM applies ground to the coil side of the low speed fan relay, which is COOL/FAN 1 relay 28. This energizes the coil and applies voltage directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to the left fan through the de-energized series/parallel relay, which is COOL/FAN SER/PAR relay 29 so that both operate at low speed.

In high speed operation, the ECM applies a ground to the coil side of the low speed relay, the series/parallel relay, and the high speed fan relay, which is COOL/FAN relay 30. On the COOL/FAN relay, the energized coil closes the switch side of the relay and applies voltage directly to the right cooling fan through the switch side of the relay. At the same time, the ECM energizes the series/parallel relay pulling the switch side over, providing a direct path to ground for the left cooling fan, which has voltage applied through the energized low speed relay. In high speed mode, the fans are operated as a parallel circuit with full voltage applied to each.

Diagnostic Aids

The ECM has the capability of providing command to the fan relays even while a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know which fans are being commanded ON by the ECM.

Schematic Reference

Engine Cooling Schematics

Description and Operation

Cooling Fan Description and Operation

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that the following DTCs are not set: P0480 or P0481. If either of the DTCs is set, repair the DTC first.
2. Verify cooling fan operation using the scan tool commands listed below: Fan relay 1 ON-Both fans run at low speed. Fan relays 2 and 3 ON-The right fan runs at high speed, the left fan is OFF. Fan relays 1, 2 and 3 ON-Both fans run at high speed.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, disconnect the low speed fan relay, which is COOL/FAN SER/PAR fan relay 29.
2. Ignition ON, activate the cooling fan relay 1 with a scan tool. The fan should be OFF. If the fan is activated, test the left fan ground circuit for a short to ground.
3. Ignition OFF, disconnect the remaining fan relays.
4. Connect a 30A fused jumper between the normally-open switch contact terminals at the low speed relay connector in order to complete the left fan ground circuit. Leave this jumper in place for the remainder of this procedure.
5. One at a time, connect a 30A fused jumper between the positive terminal at the battery and the fan voltage supply circuit terminal at each relay connection and verify the appropriate fan activation. If the appropriate fan does not activate, test the fan voltage supply circuit for a short to ground or open/high resistance. If the circuit tests normal, test the fan ground circuit for open/high resistance. If the circuits test normal, replace the fan.
6. Ignition ON, connect a 30A fused jumper between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal at the low speed fan relay, which is COOL/FAN 1 relay 28, and then the high speed fan relay, which is COOL/FAN 2 relay 30 connections and verify the appropriate fan activation. If the appropriate fan does not activate, test the relay switch voltage supply circuit for a short to ground or high resistance.
7. If the circuits and fans test normal, replace the relay.

1. «Underhood Electrical Center or Junction Block Replacement»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
3. «Cooling Fan and Shroud Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)
4. «Control Module References»(/chevrolet/malibu/vii-2008-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for replacement, setup, and programming

Ignition ON, command the fan relay ON and OFF with a scan tool. Observe to verify that the appropriate fan turns ON and OFF with each command.

Engine Overheating

Loss of Coolant

Thermostat Diagnosis

Note. This procedure is not used in Brazil.

Thermostat Test Procedure Using Glycol

Inspect the operation of the thermostat by hanging the thermostat on a hook in a 33 percent glycol solution.

In order to inspect if the thermostat valve is opening properly, perform the following test

1. Completely submerge the thermostat in a glycol solution. The solution should be 11°C (22°F) above the temperature indicated on the thermostat valve.
2. Thoroughly agitate the solution. Under these conditions, the thermostat valve should open.

In order to inspect if the thermostat valve is closing properly, perform the following test

1. Completely submerge the thermostat in a glycol solution. The solution should be 6°C (10°F) below the temperature indicated on the thermostat valve.
2. Thoroughly agitate the solution. Under these conditions, the thermostat valve should close completely.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/malibu/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The optional coolant heater operates using 110-volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather. There is an internal thermal switch in the power cord that prevents operation above -18°C (0°F). The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Wiring Repairs»(/chevrolet/malibu/vii-2008-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

1. Test the engine coolant heater for an open or short to ground. If open or shorted, replace the heater.
2. If the heater tests normal, replace the coolant heater power cord.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Coolant Heater Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (LE5)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Coolant Heater Cord Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Cord Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Cord Replacement (LE5)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Cord Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Fails To Reach Normal Operating Temperature

Special Tools

1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. J 42401 Radiator Cap/Surge Tank Test Adapter. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the pressure cap.
2. Wash the pressure cap sealing surface with water.
3. Use the J 24460-01 (1) with J 42401 (2) in order to test the pressure cap. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Test the pressure cap for the following conditions: Pressure release when the J 24460-01 exceeds the pressure rating of the pressure cap. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) . Maintain the rated pressure for at least 10 seconds. Note the rate of pressure loss.
5. Replace the pressure cap under the following conditions: The pressure cap does not release pressure which exceeds the rated pressure of the cap. The pressure cap does not hold the rated pressure.

1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. J 42401 Radiator Cap / Surge Tank Test Adapter. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

Cooling System Leak Testing

1. Remove the pressure cap.
2. Test the operation of the pressure cap. Refer to «Pressure Cap Testing»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Wash the pressure cap mating surface with water.
4. Use the J 24460-01 with J 42401 in order to apply pressure to the cooling system. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) . Do not exceed the pressure cap rating.
5. The cooling system should hold the rated pressure for at least 2 minutes. Observe the gauge for any pressure loss.
6. Repair any leaks as required.

J 26568 Coolant and Battery Fluid Tester. See Special Tools .

Draining Procedure

1. Unscrew the surge tank cap to remove vacuum when draining coolant.
2. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
3. Place a container under the radiator drain.
4. Unscrew the radiator drain plug until coolant flows out the radiator drain.
5. If a complete block drain is required, remove the coolant drain plugs. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.5L engine, «Engine Block Disassemble»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-off-vehicle-1-of-3__engine-block-disassemble) for the 3.6L engine.
6. Follow the appropriate procedure based on the condition of the coolant: Normal in appearance-Follow the filling procedure. Discolored-Follow the flush procedure. Refer to «Flushing»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Fill Procedure

1. Install the engine block coolant drain plugs. Refer to the appropriate procedure: «Engine Block Assemble»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__engine-block-assemble) for the 3.5L engine. «Engine Block Assemble»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-off-vehicle-2-of-3__engine-block-assemble) for the 3.6L engine.
2. Close the radiator drain plug.
3. Lower the vehicle.
4. Vehicle should be level.
5. Add a mixture of 50/50 DEX-COOL® antifreeze and clean drinkable water until the level stabilizes approximately 1" (25.4 mm) above the weld seam on the surge tank. Refer to «Approximate Fluid Capacities (Except Hybrid)»(/chevrolet/malibu/vii-2008-2012/remont/lubrication-system/#maintenance-and-lubrication__approximate-fluid-capacities-except-hybrid) .
6. Install the surge tank cap.
7. Start the engine and run at 2,000 RPM until the engine cooling fans turn ON.
8. Turn the engine OFF and allow the engine to cool down.
9. Remove the surge tank cap.
10. Refill to approximately 1" (25.4 mm) above the weld seam on the surge tank.
11. Install the surge tank cap.
12. Inspect the concentration of the engine coolant using J 26568 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
13. Inspect the concentration of the engine coolant using J 26568 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
14. Install the surge tank cap.
15. Rinse away any excess coolant from the engine and the engine compartment.

Tools Required

1. J 26568 Coolant and Battery Fluid Tester. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. J 42401 Radiator Pressure Adapter. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. GE-47716 Vac N Fill Coolant Refill Tool. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Unscrew the surge tank cap to remove vacuum when draining the coolant.
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
3. Place a container under the radiator drain.
4. Unscrew the radiator drain plug until coolant flows out the radiator drain.
5. If a complete block drain is required, remove the drain plugs. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-24l-repair-instructions-off-vehicle-1-of-2) for the 2.4L engine, or «Draining Fluids and Oil Filter Removal»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.5L engine, or «Engine Block Disassemble»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-off-vehicle-1-of-3__engine-block-disassemble) for the 3.6L engine.
6. Follow the appropriate procedure based on the condition of the coolant. Normal in appearance-follow the filling procedure. Discolored-follow the flush procedure. Refer to «Flushing»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Vac N Fill Procedure

If a complete engine block drain was required, install the engine block drain plugs. Refer to the appropriate procedure

1. «Engine Block Assemble»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-24l-repair-instructions-off-vehicle-1-of-2__engine-block-assemble) for the 2.4L engine
2. «Engine Block Assemble»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__engine-block-assemble) for the 3.5L engine
3. «Engine Block Disassemble»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-off-vehicle-1-of-3__engine-block-disassemble) for the 3.6L engine

1. Install J-42401-2 into the surge tank fill neck.
2. Install J-42401-3 to the surge tank fill neck.
3. Attach the Vac N Fill cap to the J-42401-3.
4. Attach the Vac N Fill cap to the vehicles coolant fill port.
5. Attach the vacuum gauge assembly to the Vac N Fill cap.
6. Attach the fill hose to the barb fitting on the vacuum gauge assembly. Ensure the valve is closed.
7. Pour the coolant mixture into the graduated reservoir.
8. Place the fill hose in the graduated reservoir.
9. Install the vacuum tank on the graduated reservoir with the fill hose routed through the cut-out area in the vacuum tank.
10. Attach the venturi assembly to the vacuum tank.
11. Attach a shop air hose to the venturi assembly. Ensure the valve on the venturi assembly is closed.
12. Attach the vacuum hose to the vacuum gauge assembly and the vacuum tank.
13. Open the valve on the venturi assembly. The vacuum gauge will begin to rise and a hissing noise will be present.
14. Continue to draw vacuum until the needle stops rising. This should be 610-660 mm Hg (24-26 in Hg). Cooling hoses may start to collapse. This is normal due to vacuum draw.
15. To aid in the fill process, position the graduated reservoir above the coolant fill port.
16. Slowly open the valve on the vacuum gauge assembly. When the coolant reaches the top of the fill hose, close the valve. This will eliminate air from the fill hose.
17. Close the valve on the venturi assembly.
18. If there is a suspected leak in the cooling system, allow the system to stabilize under vacuum and monitor for vacuum loss. If vacuum loss is observed, refer to «Loss of Coolant»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
19. Open the valve on the vacuum gauge assembly. The vacuum gauge will drop as coolant is drawn into the system.
20. Once the vacuum gauge reaches zero, close the valve on the vacuum gauge assembly and repeat steps 11-17.
21. Remove the J-42401-3 from the surge tank fill neck.
22. Remove J-42401-2 from the surge tank fill neck.
23. Detach the Vac N Fill cap from the vehicles coolant fill port.
24. Add coolant to the system as necessary.
25. Inspect the concentration of the coolant mixture using J 26568 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
26. Detach the vacuum hose from the vacuum gauge assembly.
27. Attach the extraction hose to the vacuum hose.
28. Open the valve on the venturi assembly to start a vacuum draw.
29. Use the extraction hose to draw out coolant to the proper level.
30. Install the surge tank cap.
31. The vacuum tank has a drain valve on the bottom of the tank. Open the valve to drain coolant from the vacuum tank into a suitable container for disposal.

Flushing

1. Apply the park brake.
2. Drain the coolant. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Fill the coolant system with clean drinkable water. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Start the engine and run at 2,000 RPM until the thermostat opens.
5. Turn OFF the engine.
6. Drain the coolant system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Repeat the above procedure until the water from the coolant system is colorless.
8. Drain the coolant system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
9. Add 3.8 liters (1.0 gal) of concentrated antifreeze since there will be some water in the system.
10. Add a mixture of 50/50 DEX-COOL® antifreeze and clean drinkable water until the level stabilizes at the weld seam on the surge tank. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

Radiator Cleaning

1. Some conditions may require the use of warm water and a mild detergent.
2. Clean the A/C condenser fins.
3. Clean between the A/C condenser and radiator.
4. Clean the radiator cooling fins.
5. Straighten any damaged cooling fins.

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Removal Procedure

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air cleaner air duct. Refer to the following: «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) for the 2.4L engine «Air Cleaner Inlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) for the 3.5L engine «Air Cleaner Inlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) for the 3.6L engine
3. Remove the upper radiator air deflector. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Remove the transmission oil cooler pipes from the radiator. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-4t45-e-repair-instructions-on-vehicle) for the 4T45-E transaxle.
5. Loop a rope around each of the upper 2 tabs of the condenser and tie a rope around the upper tie bar.
6. Remove the upper radiator support bracket bolts.
7. Remove the upper radiator support brackets.
8. Pry upward on the fan shroud tabs at the radiator clips to release the fan shroud from the radiator.
9. Remove the lower radiator air deflector. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
10. Lower the vehicle.
11. Remove the radiator inlet hose from the radiator. Refer to «Radiator Inlet Hose Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
12. Remove the radiator outlet hose from the radiator. Refer to «Radiator Outlet Hose Replacement (LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
13. Disconnect the cooling fan wire harness connectors.
14. Remove the A/C compressor and condenser hose assembly. Refer to «Air Conditioning Compressor and Condenser Hose Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor and Condenser Hose Replacement (LZ4, LZE)»(/chevrolet/malibu/vii-2008-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor and Condenser Hose Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
15. Raise the vehicle.
16. Remove the lower radiator support bracket bolts.
17. Remove the lower radiator support brackets.
18. Remove the transmission oil cooler pipe clip from the fan shroud.
19. Remove the fan shroud assembly.

Installation Procedure

1. Install the fan shroud assembly.
2. Install the transmission oil cooler pipes to the radiator. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-4t45-e-repair-instructions-on-vehicle) for the 4T45-E transaxle.
3. Install the transmission oil cooler pipe clip to the fan shroud.
4. Install the lower radiator support brackets.
5. Install the lower radiator support bracket bolts and tighten to 60 N.m (44 lb ft).
6. Install the cooling fan wire harness connectors.
7. Install the radiator outlet hose to the radiator. Refer to «Radiator Outlet Hose Replacement (LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Install the lower radiator air deflector. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
9. Lower the vehicle.
10. Snap fan shroud tabs into the radiator clips.
11. Remove the rope attached to the condenser and upper tie bar.
12. Install the upper radiator support brackets.
13. Install the upper radiator support bracket bolts and tighten to 10 N.m (89 lb in).
14. Install the radiator inlet hose to the radiator. Refer to «Radiator Inlet Hose Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
15. Install the A/C compressor and condenser hose assembly. Refer to «Air Conditioning Compressor and Condenser Hose Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor and Condenser Hose Replacement (LZ4, LZE)»(/chevrolet/malibu/vii-2008-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor and Condenser Hose Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
16. Install the upper radiator air deflector. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
17. Install the air cleaner air duct. Refer to the following: «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) for the 2.4L engine «Air Cleaner Inlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) for the 3.5L engine «Air Cleaner Inlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) for the 3.6L engine
18. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
19. Inspect the transmission fluid level. Refer to «Transmission Fluid Level and Condition Check»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-4t45-e-symptom-troubleshooting-and-diagnosis) for the 4T45-E transaxle or «Transmission Fluid Level and Condition Check»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-6t706t75-symptom-troubleshooting-and-diagnosis__transmission-fluid-level-and-condition-check) for the 6T70/6T75 transaxle.

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Drain the coolant from the engine block at the water pump drain. After the coolant has drained, tighten the drain bolt.
3. Lower the vehicle.
4. Remove the battery tray. Refer to «Battery Tray Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
5. Disconnect the engine wiring harness electrical connector (1) from the engine coolant temperature (ECT) sensor.
6. Remove the heated oxygen sensor (HO2S) electrical connector rosebud clip from the thermostat housing.
7. Reposition the radiator outlet hose clamp at the thermostat cover.
8. Remove the radiator outlet hose from the thermostat cover.
9. Remove the exhaust heat shield bolts (1).
10. Remove the exhaust heat shield.
11. Remove the auxiliary heater water pump hose clip (1) from the heater outlet hose.
12. Reposition the auxiliary heater water pump hose clamp at the thermostat housing.
13. Remove the auxiliary heater water pump hose (2) from the thermostat housing.
14. Reposition the heater inlet hose clamp at the thermostat housing.
15. Remove the heater inlet hose (3) from the thermostat housing.
16. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
17. Remove the ECT sensor, if necessary.
18. Remove the thermostat housing bolts.
19. Remove the thermostat from the vehicle.
20. Remove the water transfer pipe from the thermostat housing, if necessary.
21. Remove and discard the water transfer pipe O-ring seals, if necessary.
22. Remove the thermostat cover bolts and cover, if necessary.
23. Remove the thermostat, if necessary.
24. Remove and discard the thermostat cover O-ring seal, if necessary.
25. Remove all debris and thread sealant from the engine coolant temperature (ECT) sensor and bolt holes if the housing is being re-used.

1. Install a NEW thermostat cover O-ring seal into the recess groove.
2. Install the thermostat, if necessary.
3. Install the thermostat cover bolts, if necessary. Tighten the bolts to 10 N.m (89 lb in).
4. Install a NEW thermostat housing to engine gasket onto the thermostat housing.
5. Load the thermostat housing assembly into position.
6. Install NEW O-ring seals onto the water feed pipe.
7. Install the water feed pipe into the thermostat housing aligning locator tab.
8. Align the water pipe to water pump.
9. Seat the water feed O-ring seal by pushing inward toward the water pump. Take care not to tear or damage the O-ring.
10. Position the thermostat housing against the engine.
11. Install the thermostat housing bolts and tighten to 10 N.m (89 lb in).
12. If reinstalling the old sensor, coat the threads with sealant. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-24l-specifications__adhesives-fluids-lubricants-and-sealers) .
13. Install the ECT sensor, if necessary. Tighten the sensor to 20 N.m (15 lb ft).
14. Lower the vehicle.
15. Install the heater inlet hose (3) to the thermostat housing.
16. Position the heater inlet hose clamp at the thermostat housing.
17. Install the auxiliary heater water pump hose (2) to the thermostat housing.
18. Position the auxiliary heater water pump hose clamp at the thermostat housing.
19. Install the auxiliary heater water pump hose clip (1) to the heater outlet hose.
20. Install the exhaust heat shield.
21. Install the exhaust heat shield bolts. Tighten the studs to 22 N.m (16 lb ft).
22. Install the radiator outlet hose to the thermostat cover.
23. Position the radiator outlet hose clamp at the thermostat cover.
24. Connect the engine wiring harness electrical connector (1) to the ECT sensor.
25. Install the HO2S electrical connector rosebud clip to the thermostat housing.
26. Install the battery tray. Refer to «Battery Tray Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
27. Verify the drain valves at the radiator and water pump are closed.
28. Lower the vehicle.
29. Fill the cooling system. Refer to «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Partially drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions)
3. Remove the radiator outlet hose from the thermostat housing.
4. Remove the heater inlet and outlet hoses.
5. Remove the surge tank outlet hose.
6. Remove the thermostat housing bolts (1).
7. Remove the housing.

1. Install the thermostat housing bolts and tighten to 10 N.m (89 lb in).
2. Install the surge tank outlet hose.
3. Install the heater inlet and outlet hoses.
4. Install the radiator outlet hose to the thermostat housing.
5. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions)
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
3. Reposition the radiator outlet hose clamp at the thermostat housing.
4. Remove the radiator outlet hose from the thermostat housing.
5. Remove the thermostat housing bolt/stud.
6. Remove the thermostat housing and gasket.
7. Clean the gasket surfaces.

1. Position a NEW gasket and the thermostat housing to the engine block.
2. Install the thermostat housing bolt/stud and tighten to 10 N.m (89 lb in).
3. Install the radiator outlet hose to the thermostat housing.
4. Position the radiator outlet hose clamp at the thermostat housing.
5. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Inspect the system for leaks.

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the water pump drain plug and drain the coolant from the engine block at the water pump drain.
3. Lower the vehicle.
4. Disconnect the engine coolant temperature (ECT) sensor electrical connector (1).
5. Disconnect the heated oxygen sensor (HO2S) electrical connector clip from the bracket.
6. Remove the ECT sensor.
7. Remove the surge tank outlet hose from the thermostat housing.
8. Reposition the radiator outlet hose clamp at the thermostat housing.
9. Remove the radiator outlet hose from the thermostat housing.
10. Remove the exhaust heat shield bolts.
11. Remove the exhaust heat shield.
12. Reposition the heater inlet and outlet hose clamps at the thermostat housing pipes.
13. Disconnect the heater inlet (1) and outlet (2) hoses from the thermostat housing pipes.
14. Remove the thermostat housing bolts.
15. Remove the thermostat housing from the vehicle.
16. Remove the water transfer pipe from the thermostat housing, if necessary.
17. Remove and discard the water transfer pipe O-ring seals, if necessary.
18. Remove the thermostat housing cover bolts and cover, if necessary.
19. Remove the thermostat, if necessary.
20. Remove and discard the thermostat housing O-ring seal, if necessary.
21. Remove all debris and thread sealant from the engine coolant temperature sensor and bolt holes if the housing is being re-used.

1. Install a NEW thermostat housing cover O-ring seal into the recess groove.
2. Install the thermostat, if necessary.
3. Install the thermostat housing cover bolts, if necessary. Tighten the bolts to 10 N.m (89 lb in).
4. Install a NEW thermostat housing to engine O-ring seal onto the thermostat housing.
5. Load the thermostat housing assembly into position while the vehicle is lowered.
6. Install NEW O-ring seals onto the water feed pipe.
7. Install the water feed pipe into the thermostat housing aligning locator tab.
8. Align the water pipe to water pump.
9. Seat the water feed O-ring seal by pushing inward toward the water pump. Take care not to tear or damage the O-ring.
10. Position the thermostat housing against the engine.
11. Install the thermostat housing bolts and tighten to 10 N.m (89 lb in).
12. Connect the heater inlet (1) and outlet (2) hoses to the thermostat housing pipes.
13. Position the heater inlet and outlet hose clamps at the thermostat housing pipes.
14. Install the exhaust heat shield.
15. Install the exhaust heat shield bolts and tighten to 23 N.m (17 lb ft).
16. Install the radiator outlet hose to the thermostat housing.
17. Position the radiator outlet hose clamp at the thermostat housing.
18. Install the radiator outlet hose to the surge tank.
19. Position the radiator outlet hose clamp at the surge tank.
20. Apply sealant to the threads of the ECT sensor. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__adhesives-fluids-lubricants-and-sealers) .
21. Install the ECT sensor and tighten to 20 N.m (15 lb ft).
22. Connect the ECT sensor electrical connector (1).
23. Connect the HO2S electrical connector clip to the bracket.
24. Apply sealant to the water pump drain plug. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__adhesives-fluids-lubricants-and-sealers)
25. Install the water pump drain plug and tighten to 20 N.m (15 lb ft).
26. Verify the drain valves at the radiator and water pump are closed.
27. Fill the cooling system. Refer to «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
28. Verify the repair and inspect for any leaks.

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Reposition the radiator outlet hose clamp at the thermostat cover.
3. Remove the radiator outlet hose from the thermostat cover.
4. Remove the thermostat cover bolts and cover.
5. Remove the thermostat.
6. Remove and discard the thermostat cover O-ring seal.

1. Install a NEW thermostat cover O-ring seal.
2. Install the thermostat.
3. Install the thermostat cover bolts and tighten to 10 N.m (89 lb in).
4. Install the radiator outlet hose to the thermostat cover.
5. Position the radiator outlet hose clamp at the thermostat cover.
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Partially drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the radiator outlet hose from the thermostat housing.
3. Remove the heater inlet and outlet hoses.
4. Remove the surge tank outlet hose.
5. Remove the thermostat housing bolts (1).
6. Remove the housing.
7. Remove the thermostat (2) and discard the thermostat gasket.

1. Install the thermostat (2) with a NEW thermostat gasket.
2. Install the thermostat housing bolts (1) and tighten to 10 N.m (89 lb in).
3. Install the surge tank outlet hose.
4. Install the heater inlet and outlet hoses.
5. Install the radiator outlet hose to the thermostat housing.
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
3. Reposition the radiator outlet hose clamp at the thermostat housing.
4. Remove the radiator outlet hose from the thermostat housing.
5. Remove the thermostat housing bolt/stud.
6. Remove the thermostat housing and gasket.
7. Remove the thermostat.
8. Clean the gasket surfaces.

1. Install a NEW thermostat.
2. Position a NEW gasket and the thermostat housing to the engine block.
3. Install the thermostat housing bolt/stud and tighten to 10 N.m (89 lb in).
4. Install the radiator outlet hose to the thermostat housing.
5. Position the radiator outlet hose clamp at the thermostat housing.
6. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
7. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Inspect the system for leaks.

1. Remove the intake manifold cover. Refer to «Fuel Injector Sight Shield Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .
2. Remove the generator. Refer to «Generator Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the drive belt idler pulleys. Refer to «Drive Belt Idler Pulley Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) .
4. Remove the power steering pump. Refer to «Power Steering Pump Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/electronic-steering/#power-steering-system) .
5. Reposition the radiator surge tank inlet hose clamp (1) at the surge tank inlet pipe.
6. Remove the radiator surge tank inlet hose from the inlet pipe. Position the hose out of the way.
7. Remove the radiator surge tank pipe bolts (2).
8. Remove the radiator surge tank pipe from the crossover pipe.
9. Reposition the radiator inlet hose clamp at the crossover pipe.
10. Remove the radiator inlet hose from the crossover pipe.
11. Reposition the thermal bypass hose clamp at the crossover pipe.
12. Remove the thermal bypass hose from the crossover pipe.
13. Remove the coolant crossover pipe bolts (1-4).
14. Remove the coolant crossover pipe.

1. Position the coolant crossover pipe to the cylinder heads.
2. Install the coolant crossover pipe bolts (1-4) and tighten to 50 N.m (37 lb ft).
3. Install the thermal bypass hose to the crossover pipe.
4. Position the thermal bypass hose clamp at the crossover pipe.
5. Install the radiator inlet hose to the crossover pipe.
6. Position the radiator inlet hose clamp at the crossover pipe.
7. Install the radiator surge tank pipe to the crossover pipe.
8. Install the radiator surge tank pipe bolts (2) and tighten to 10 N.m (89 lb in).
9. Install the radiator surge tank inlet hose to the inlet pipe.
10. Position the radiator surge tank inlet hose clamp (1) at the surge tank inlet pipe.
11. Install the power steering pump. Refer to «Power Steering Pump Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/electronic-steering/#power-steering-system) .
12. Install the drive belt idler pulleys. Refer to «Drive Belt Idler Pulley Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) .
13. Install the generator. Refer to «Generator Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
14. Install the intake manifold cover. Refer to «Fuel Injector Sight Shield Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .

1. Remove the intake manifold cover. Refer to «Fuel Injector Sight Shield Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .
2. Remove the surge tank inlet hose. Refer to «Radiator Surge Tank Inlet Hose/Pipe Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the fuel feed pipe line nut (2).
4. Remove the fuel feed line clip from the stud and reposition the fuel feed line.
5. Remove the coolant air bleed hose/pipe bolt (3) from the upper intake manifold.
6. Reposition the coolant air bleed hose clamp (2) at the water outlet.
7. Remove the coolant air bleed hose from the water outlet.
8. Remove the coolant air bleed hose/pipe from the engine.

1. Install the coolant air bleed hose/pipe to the engine.
2. Install the coolant air bleed hose to the water outlet.
3. Position the coolant air bleed hose clamp (2) at the water outlet.
4. Install the coolant air bleed hose/pipe bolt (3) to the upper intake manifold and tighten to 10 N.m (89 lb in).
5. Position the fuel feed line and install the fuel feed line clip to the stud.
6. Install the fuel feed pipe line nut (2) and tighten to 10 N.m (89 lb in).
7. Install the surge tank inlet hose. Refer to «Radiator Surge Tank Inlet Hose/Pipe Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Install the intake manifold cover. Refer to «Fuel Injector Sight Shield Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .

Scheme 17

1. J 25025-5 Dial Indicator Mounting Post. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. J 43651 Water Pump Holding Tool. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the thermostat housing. Refer to «Engine Coolant Thermostat Housing Replacement (LE5)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the coolant heater. Refer to «Coolant Heater Replacement (LE5)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the water pump access plate from the front cover.
4. Install the J 43651 into position. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Tighten the bolts on the water pump holding tool into the threads on the water pump sprocket.
6. Install the access cover bolts that were removed earlier to secure the water pump holding tool to the front cover assembly.
7. Remove the 3 inner water pump sprocket to water pump bolts through the holes in the water pump holding tool.
8. Remove the 2 water pump bolts.
9. Remove the rear 2 water pump bolts.
10. Remove the engine wiring harness clip nut from the water pump stud.
11. Remove the engine wiring harness clip from the stud.
12. Remove the water pump.

1. Apply sealant to the water pump drain plug. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__adhesives-fluids-lubricants-and-sealers)
2. Install the water pump drain plug and tighten to 20 N.m (15 lb ft).
3. Using the J 25025-5 , or a guide pin align the pin with the water pump holding tool. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Position the water pump against the engine block and hand tighten the water pump bolts.
5. Install the inner water pump sprocket bolts. After 2 are snug, remove the guide pin and install the 3rd bolt. Tighten the water pump bolts to 25 N.m (18 lb ft).
6. Tighten the water pump sprocket bolts last to 10 N.m (89 lb in).
7. Remove the J 43651 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Install the coolant heater. Refer to «Coolant Heater Replacement (LE5)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
9. Install the water pump access plate and bolts and tighten to 10 N.m (89 lb in).
10. Install the thermostat housing. Refer to «Engine Coolant Thermostat Housing Replacement (LE5)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

EN 46104 Water Pump Pulley Holding Tool

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .
3. Use the EN 46104 in order to retain the water pump pulley.
4. Remove the water pump pulley bolts.
5. Remove the water pump pulley.
6. Remove the water pump bolts.
7. Remove the water pump.
8. Remove and DISCARD the water pump seal.
9. Carefully clean the water pump sealing surfaces.

1. Install a NEW water pump seal.
2. Install the water pump.
3. Install the water pump bolts and tighten to 10 N.m (89 lb in).
4. Install the water pump pulley and the water pump pulley bolts.
5. Use the EN 46104 in order to retain the water pump pulley.
6. Install the water pump pulley bolts and tighten to 10 N.m (89 lb in).
7. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .
8. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

J 43651 Water Pump Holding Tool. See Special Tools .

1. Remove the thermostat housing. Refer to «Engine Coolant Thermostat Housing Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the engine splash shield. Refer to «Engine Splash Shield Replacement - Right Side»(/chevrolet/malibu/vii-2008-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
3. Remove the water pump access plate from the front cover.
4. Drain the coolant from the water pump using the plug at the bottom of the pump.
5. Install the J 43651 (1) into position. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Tighten the bolts on the water pump holding tool into the threads on the water pump sprocket.
7. Install the access cover bolts that were removed earlier to secure the water pump holding tool to the front cover assembly.
8. Remove the 3 inner water pump sprocket to water pump blots.
9. Remove the 2 water pump bolts.
10. Remove the rear 2 water pump bolts.
11. Remove the water pump.
12. Remove and discard the water pump O-ring seal.

1. Install a NEW water pump O-ring seal.
2. Using the guide pin, align the pin with the water pump holding tool.
3. Position the water pump against the engine block and hand tighten the water pump bolts.
4. Install the inner water pump sprocket bolts. After 2 are snug, remove the guide pin and install the 3rd bolt. Tighten the water pump bolts to 25 N.m (18 lb ft).
5. Tighten the water pump sprocket bolts last to 10 N.m (89 lb in).
6. Remove the J 43651 (1). See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Install the water pump access plate and bolts. Tighten the bolts to 10 N.m (89 lb in).
8. Install the engine splash shield. Refer to «Engine Splash Shield Replacement - Right Side»(/chevrolet/malibu/vii-2008-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
9. Install the thermostat housing. Refer to «Engine Coolant Thermostat Housing Replacement (LAT)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Loosen the water pump pulley bolts.
3. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) .
4. Remove the water pump pulley bolts and pulley.
5. Remove the water pump bolts.
6. Remove the water pump and gasket.
7. Clean the water pump mating surfaces.

1. Position a NEW water pump gasket and the water pump to the engine front cover.
2. Install the water pump bolts and tighten to 25 N.m (18 lb ft).
3. Install the water pump pulley and bolts.
4. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) .
5. Tighten the water pump pulley bolts to 25 N.m (18 lb ft).
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Inspect for leaks.

J 38185 Hose Clamp Pliers. See Special Tools .

1. Drain the coolant. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Loop a rope around each of the upper 2 tabs of the condenser and tie the rope around the upper tie bar.
3. Remove the upper radiator support brackets. Refer to «Radiator Support Bracket Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Reposition the radiator inlet hose clamp at the radiator using the J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Remove the radiator inlet hose from the radiator.
6. Remove the right engine splash shield retainers.
7. Remove the right engine splash shield.
8. Remove the left engine splash shield retainers.
9. Remove the left engine splash shield.
10. Reposition the radiator outlet hose clamp at the radiator using the J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
11. Remove the radiator outlet hose from the radiator.
12. Remove the transmission oil cooler pipes from the transmission. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-4t45-e-repair-instructions-on-vehicle) .
13. Remove the lower radiator support bracket bolts.
14. Remove the lower radiator support brackets.
15. Remove the radiator lower mounts.
16. Remove and discard the condenser mounting bolts from the radiator.
17. Push upward on the radiator and downward on the condenser to unsnap the condenser mounting tabs from the radiator clips.
18. Remove and discard the condenser mounting nuts from the radiator.
19. Remove the radiator air side seals.
20. Remove the radiator and cooling fan shroud assembly from the vehicle.
21. Pry upward on the fan shroud tabs at the radiator clips.
22. Remove the cooling fan and shroud assembly from the radiator.

1. Install the cooling fan and shroud assembly to the radiator.
2. Snap the fan shroud tabs into the radiator clips.
3. Install the radiator and cooling fan shroud assembly to the vehicle.
4. Install the radiator air side seals onto the condenser mounting tabs on the radiator.
5. Install the condenser mounting nuts to the radiator.
6. Insert the condenser mounting tabs into the radiator clips.
7. Install the condenser to the radiator bolts and tighten to 6 N.m (53 lb in).
8. Bend the radiator air side seals and insert the seals into the channel of the intake air splash shields.
9. The radiator air side seals must be in the proper position for proper air flow.
10. Install the radiator lower mounts.
11. Install the lower radiator support brackets.
12. Install the lower radiator support bracket bolts and tighten to 60 N.m (44 lb ft).
13. Install the transmission oil cooler pipes to the transmission. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-4t45-e-repair-instructions-on-vehicle) .
14. Install the radiator outlet hose to the radiator.
15. Reposition the radiator outlet hose clamp at the radiator using the J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
16. Install the left engine splash shield.
17. Install the left engine splash shield retainers.
18. Install the right engine splash shield.
19. Install the right engine splash shield retainers.
20. Lower the vehicle.
21. Install the radiator inlet hose to the radiator.
22. Reposition the radiator inlet hose clamp at the radiator using the J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
23. Remove the rope attached to the condenser and upper tie bar.
24. Install the upper radiator support brackets. Refer to «Radiator Support Bracket Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
25. Fill the coolant. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
26. Inspect the transmission fluid level. Refer to «Transmission Fluid Level and Condition Check»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-4t45-e-symptom-troubleshooting-and-diagnosis) .

J 38185 Hose Clamp Pliers. See Special Tools .

1. Drain the coolant. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Loop a rope around each of the upper 2 tabs of the condenser and tie the rope around the upper tie bar.
3. Remove the upper radiator support brackets. Refer to «Radiator Support Bracket Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Reposition the radiator inlet hose clamp at the radiator using the pliers J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Remove the radiator inlet hose from the radiator.
6. Remove the right engine splash shield retainers.
7. Remove the right engine splash shield.
8. Remove the left engine splash shield retainers.
9. Remove the left engine splash shield.
10. Reposition the radiator outlet hose clamp at the radiator using the pliers J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
11. Remove the radiator outlet hose from the radiator.
12. Remove the transmission oil cooler pipes from the radiator.
13. Remove the lower radiator support bracket bolts.
14. Remove the lower radiator support brackets.
15. Remove the radiator lower mounts.
16. Remove and discard the condenser mounting bolts from the radiator.
17. Push upward on the radiator and downward on the condenser to unsnap the condenser mounting tabs from the radiator clips.
18. Remove and discard the condenser mounting nuts from the radiator.
19. Remove the radiator air side seals.
20. Remove the radiator and cooling fan shroud assembly from the vehicle.
21. Pry upward on the fan shroud tabs at the radiator clips.
22. Remove the cooling fan and shroud assembly from the radiator.

1. Install the cooling fan and shroud assembly to the radiator.
2. Snap the fan shroud tabs into the radiator clips.
3. Install the radiator and cooling fan shroud assembly to the vehicle.
4. Install the radiator air side seals onto the condenser mounting tabs on the radiator.
5. Install the condenser mounting nuts to the radiator.
6. Insert the condenser mounting tabs into the radiator clips.
7. Install the condenser to the radiator bolts and tighten to 6 N.m (53 lb in).
8. Bend the radiator air side seals and insert the seals into the channel of the intake air splash shields.
9. The radiator air side seals must be in the proper position for proper air flow.
10. Install the radiator lower mounts.
11. Install the lower radiator support brackets.
12. Install the lower radiator support bracket bolts and tighten to 60 N.m (44 lb ft).
13. Install the transmission oil cooler pipes to the radiator.
14. Install the radiator outlet hose to the radiator.
15. Reposition the radiator outlet hose clamp at the radiator using the pliers J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
16. Install the left engine splash shield.
17. Install the left engine splash shield retainers.
18. Install the right engine splash shield.
19. Install the right engine splash shield retainers.
20. Lower the vehicle.
21. Install the radiator inlet hose to the radiator.
22. Reposition the radiator inlet hose clamp at the radiator using the pliers J 38185 . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
23. Remove the rope attached to the condenser and upper tie bar.
24. Install the upper radiator support brackets. Refer to «Radiator Support Bracket Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
25. Fill the coolant. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
26. Inspect the transmission fluid level. Refer to «Transmission Fluid Level and Condition Check»(/chevrolet/malibu/vii-2008-2012/remont/automatic-trans/#automatic-transaxle-6t706t75-symptom-troubleshooting-and-diagnosis__transmission-fluid-level-and-condition-check) .

Scheme 18

Scheme 19

1. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
2. Remove the lower radiator air deflector retainers.
3. Remove the lower radiator air deflector.

1. Install the lower radiator air deflector.
2. Install the lower radiator air deflector retainers.
3. Lower the vehicle.

1. Remove the upper front fascia. Refer to «Front Bumper Fascia Replacement»(/chevrolet/malibu/vii-2008-2012/remont/exterior-body-panels/#bumpers-and-fascia) .
2. Remove the lower radiator air baffle. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the side radiator air deflector retainer.
4. Remove the side radiator air deflector.

1. Install the side radiator air deflector.
2. Install the side radiator air deflector retainer.
3. Install the lower radiator air baffle. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Install the upper front fascia. Refer to «Front Bumper Fascia Replacement»(/chevrolet/malibu/vii-2008-2012/remont/exterior-body-panels/#bumpers-and-fascia) .

1. Remove the front fascia. Refer to «Front Bumper Fascia Replacement»(/chevrolet/malibu/vii-2008-2012/remont/exterior-body-panels/#bumpers-and-fascia) .
2. Remove the upper radiator air deflector.

1. Install the upper radiator air deflector.
2. Install the front fascia. Refer to «Front Bumper Fascia Replacement»(/chevrolet/malibu/vii-2008-2012/remont/exterior-body-panels/#bumpers-and-fascia) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Disconnect the engine coolant heater cord (1) from the engine coolant heater.
3. Remove the engine coolant heater.
4. Clean the engine coolant heater opening.

1. Apply sealer to the threads of the engine coolant heater, if necessary. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system__adhesives-fluids-lubricants-and-sealers)
2. Install the engine coolant heater and tighten to 60 N.m (44 lb ft).
3. Connect the engine coolant heater cord (1) to the engine coolant heater.
4. Lower the vehicle.
5. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill-LY7, LZE, LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Inspect for leaks.

1. Raise and support vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
2. Disconnect the coolant heater cord (1).
3. Remove the coolant heater bolt.
4. Remove the coolant heater.

1. Install the coolant heater.
2. Install the coolant heater bolt and tighten to 10 N.m (89 lb in).
3. Connect the coolant heater cord (1).
4. Lower the vehicle.

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
2. Disconnect the coolant heater cord.
3. Remove the coolant heater bolt.
4. Remove the coolant heater.

1. Install the coolant heater.
2. Install the coolant heater bolt and tighten to 10 N.m (89 lb in).
3. Connect the coolant heater cord.
4. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .

1. Disconnect the engine coolant heater cord (1).
2. Remove the heater cord retaining clip from the front fender.

1. Install the heater cord retaining clip to the front fender.
2. Connect the engine coolant heater cord (1).

1. Remove the surge tank fasteners and reposition the tank aside. Refer to «Radiator Surge Tank Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Disconnect the engine coolant heater cord (1).
3. Disconnect the clip (1) from the transmission range selector lever cable bracket (2).
4. Remove the heater cord (1).

1. Install the heater cord (1).
2. Connect the clip (1) to the transmission range selector lever cable bracket (2).
3. Connect the engine coolant heater cord (1).
4. Reposition the surge tank and install the fasteners. Refer to «Radiator Surge Tank Replacement»(/chevrolet/malibu/vii-2008-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Disconnect the engine coolant heater cord.
2. Disconnect the clip from the air conditioning (A/C) line.
3. Disconnect the clip from the front compartment inner side upper rail.
4. Remove the heater cord.

1. Install the heater cord.
2. Connect the clip to the front compartment inner side upper rail.
3. Connect the clip to the A/C line.
4. Connect the engine coolant heater cord.

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
2. Disconnect the engine coolant heater cord (1) from the engine coolant heater.
3. Lower the vehicle.
4. Remove the coolant heater cord clip from the transaxle bracket.
5. Remove the coolant heater cord from the shock tower and the battery tray.

1. Install the coolant heater cord between the shock tower and the battery tray.
2. Install the coolant heater cord clip to the transaxle bracket.
3. Raise and support the vehicle.
4. Connect the engine coolant heater cord (1) to the engine coolant heater.
5. Lower the vehicle.

Scheme 20

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the engine control module (ECM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood fuse block.

During low speed operation, the ECM supplies the ground path for the low speed fan relay, which is cool/fan 1 relay 28, through the low speed cooling fan relay control circuit. This energizes the low speed fan relay coil, closes the relay contacts, and supplies battery positive voltage from the cool fan 1 fuse 17 through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the series/parallel relay, which is cool/fan ser/par relay 29, and the right cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the ECM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. The ECM supplies a ground path for the high speed fan relay, which is cool/fan 2 relay 30, and the series/parallel relay through the high speed cooling fan relay control circuit. This energizes the series/parallel relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the high fan speed relay coil is energized closing the relay contacts and provides battery positive voltage from the cool fan 2 fuse 18 on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have their own ground path. The result is a parallel circuit with both fans running at high speed.

When the request for fan activation is withdrawn, the fan may not turn OFF until the ignition switch is moved to the OFF position or the vehicle speed exceeds approximately 10 mph. This is to prevent a fan from cycling ON and OFF excessively at idle.

Cooling System Description and Operation

Note. This procedure is not used in Brazil.

Cooling Fan Control

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the powertrain control module (PCM) or engine control module (ECM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood fuse block. The ground path is provided at G106.

During low speed operation, the PCM or ECM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the cooling fan 1 relay coil, closes the relay contacts, and supplies battery positive voltage from the cool fan 1 fuse through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan S/P relay and the right cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the PCM or ECM supplies the ground path for the cooling fan 1 relay through the low speed cooling fan relay control circuit. After a 3 second delay, the PCM or ECM supplies a ground path for the cooling fan 2 relay and the cooling fan S/P relay through the high speed cooling fan relay control circuit. This energizes the cooling fan 2 relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the cooling fan S/P relay coil is energized closing the relay contacts and provides battery positive voltage from the cool fan 2 fuse on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have their own ground path. The result is a parallel circuit with both fans running at high speed.

The PCM or ECM commands Low Speed Fans ON under the following conditions

1. Engine coolant temperature exceeds approximately 106°C (223°F).
2. When A/C is requested and the ambient temperature is more than 50°C (122°F).
3. A/C refrigerant pressure exceeds 1 310 kPa (190 psi).
4. After the vehicle is shut off, if the engine coolant temperature at key-off is more than 140°C (284°F) and system voltage is more than 12 volts. The fans will stay ON for approximately 3 minutes.

The PCM or ECM commands High Speed Fans ON under the following conditions

1. Engine coolant temperature reaches 110°C (230°F).
2. A/C refrigerant pressure exceeds 1 655 kPa (240 psi).
3. When certain DTCs set

TEMP

1. The instrument panel cluster (IPC) illuminates the TEMP indicator when the powertrain control module (PCM) or engine control module (ECM) determines that the coolant temperature is more than 128°C (262°F). The IPC receives a discrete input from the PCM or ECM requesting illumination.
2. The IPC performs the display test at the start of each ignition cycle. The IPC illuminates the TEMP indicator.

Coolant Level Control

The engine cooling system contains an engine coolant level switch to alert the driver in the event of a low coolant level. When the engine coolant level in the surge tank falls below a certain level, the coolant level switch opens. When the body control module (BCM) detects an open or a high voltage level on the coolant level indicator control circuit, for at least 10 seconds, it will send a GM LAN message to the driver information center (DIC) requesting display of the low coolant level message. There is approximately a 10-second delay before the BCM sends the GM LAN message to prevent the message from being displayed, due to coolant sloshing in the surge tank.

Coolant Heater

The optional engine coolant heater (RPO K05) operates using AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather -29°C (-20°F). The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.

The cooling system's function is to maintain an efficient engine operating temperature during all engine speeds and operating conditions. The cooling system is designed to remove approximately one-third of the heat produced by the burning of the air-fuel mixture. When the engine is cold, the coolant does not flow to the radiator until the thermostat opens. This allows the engine to warm quickly.

Cooling Cycle

Coolant flows from the radiator outlet and into the water pump inlet. Some coolant flows from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost capability as the coolant warms up.

Coolant also flows from the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where the coolant absorbs heat.

The coolant then flows through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where the coolant absorbs additional heat.

Coolant is also directed to the throttle body. There the coolant circulates through passages in the casting. During initial start up, the coolant assists in warming the throttle body.

From the cylinder heads, the coolant flows to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine reaches normal operating temperature, or the coolant will flow through the thermostat and into the radiator where the coolant is cooled. At this point, the coolant flow cycle is completed.

Efficient operation of the cooling system requires proper functioning of all cooling system components. The cooling system consists of the following components.

Coolant

The engine coolant is a solution made up of a 50/50 mixture of DEX-COOL and suitable drinking water. The coolant solution carries excess heat away from the engine to the radiator, where the heat is dissipated to the atmosphere.

Radiator

The radiator is a heat exchanger consisting of a core and 2 tanks. The aluminum core is a tube and fin crossflow design that extends from the inlet tank to the outlet tank. Fins are placed around the outside of the tubes to improve heat transfer to the atmosphere.

The inlet and outlet tanks are a molded, high temperature, nylon reinforced plastic material. A high temperature rubber gasket seals the tank flange edge to the aluminum core. The tanks are clamped to the core with clinch tabs. The tabs are part of the aluminum header at each end of the core.

The radiator also has a drain cock located in the bottom of the left hand tank. The drain cock unit includes the drain cock and drain cock seal.

Heat is removed from the coolant as the coolant passes through the radiator. The fins on the core transfer heat from the coolant passing through the tubes. Air passing between the fins absorbs the heat and cools the coolant.

Pressure Cap

The pressure cap seals and pressurizes the cooling system. The cap contains a blow off, or pressure valve and a vacuum, or an atmospheric valve

1. The pressure valve is held against the seat by a spring that protects the radiator by relieving pressure that exceeds 15 psi.
2. The vacuum valve is held against the seat by a spring that permits opening of the valve to relieve vacuum created when the cooling system cools. The vacuum, if not relieved, might cause the radiator to collapse.

The pressure cap allows the cooling system pressure to build up when the temperature increases. As the pressure builds, the boiling point of the coolant increases. Therefore, the engine coolant can be safely run at a temperature much higher than the boiling point of the coolant at atmospheric pressure. The hotter the coolant becomes, the faster the heat transfers from the radiator into the cooler air.

The pressure in the cooling system can get too high. When the pressure exceeds the strength of the spring, the pressure valve rises, venting the excess pressure.

As the engine cools, the temperature of the coolant drops and a vacuum is created in the cooling system. This vacuum causes the vacuum valve to open. This equalizes the pressure in the cooling system with the atmospheric pressure, preventing the radiator from collapsing.

Coolant Recovery System

The coolant recovery system consists of a plastic coolant recovery reservoir and overflow tube. The recovery reservoir is also called a recovery tank or expansion tank. This tank is partially filled with coolant and is connected to the radiator fill neck with the overflow tube. Coolant can flow back and forth between the radiator and the reservoir.

In effect, a cooling system with a coolant recovery reservoir is a closed system. When the pressure within the cooling system gets too high, the pressure valve in the pressure cap will open. This allows the coolant, which has expanded due to heat, to flow through the overflow tube and into the recovery reservoir. As the engine cools down, the temperature of the coolant drops and a vacuum is created in the cooling system. This vacuum opens the vacuum valve in the pressure cap, allowing some of the coolant in the reservoir to be siphoned back into the radiator. Under normal operating conditions, no coolant is lost. Although the coolant level in the recovery reservoir goes up and down, the radiator and cooling system are kept full. An advantage to using a coolant recovery reservoir is the elimination of almost all air bubbles from the cooling system. Coolant without bubbles absorbs heat much better than coolant with bubbles.

Air Baffles and Seals

The cooling system uses deflectors, air baffles and air seals to increase cooling system capability. Deflectors are installed under the vehicle to redirect airflow beneath the vehicle and through the radiator to increase engine cooling. Air baffles are also used to direct airflow through the radiator and increase cooling capability. Air seals prevent air from bypassing the radiator and A/C condenser, and prevent recirculation of hot air for better hot weather cooling and A/C condenser performance.

Water Pump

The water pump is a centrifugal vane impeller type pump. The pump consists of a housing with coolant inlet and outlet passages and an impeller. The impeller is a flat plate mounted on the pump shaft with a series of flat or curved blades or vanes. When the impeller rotates, the coolant between the vanes is thrown outward by centrifugal force. The impeller shaft is supported by one or more sealed bearings, which never need to be lubricated. With a sealed bearing, grease cannot leak out, and dirt and water cannot get in.

The water pump circulates coolant throughout the cooling system. The pump is driven by the crankshaft from the drive belt.

Thermostat

The thermostat is a coolant flow control component, whose purpose is to regulate the operating temperature of the engine. The thermostat utilizes a temperature sensitive wax-pellet element, which connects to a valve through a piston. Heating causing the element to expand and exert pressure against a rubber diaphragm. This pressure forces the valve to open. Cooling causes the element to contract. This contraction allows a spring to push the valve closed.

When the coolant temperature is below 91°C (195°F), the thermostat valve remains closed. This prevents circulation of the coolant to the radiator and allows the engine to warm up quickly. After the coolant temperature reaches 91°C (195°F), the thermostat valve will open. The coolant is then allowed to circulate through the thermostat to the radiator where the engine heat is dissipated to the atmosphere. The thermostat also provides a restriction in the cooling system, even after opening. This restriction creates a pressure difference which prevents cavitation at the water pump and forces coolant to circulate through the engine block.

Transmission Oil Cooler

The transmission oil cooler is a heat exchanger and is located inside the right side end tank of the radiator. The transmission fluid temperature is regulated by the temperature of the engine coolant that surrounds the oil cooler as the transmission fluid passes through the cooler.

The transmission oil pump circulates the fluid through the feed line to the oil cooler. The fluid then flows through the cooler while the engine coolant absorbs heat from the fluid. The fluid is then pumped through the return line to the transmission.

Illustration Tool Number/ Description GE 47622 Hose Clamp Pliers GE 47716 Vac N Fill Coolant Refill Tool J 24460-01 Radiator Pressure Tester J 24731 Tempil Stick J 25025-5 Dial Indicator Mounting Post J 26568 Coolant and Battery Fluid Tester J 38185 Hose Clamp Pliers J 42220 Universal 12V Leak Detection Lamp J 42401 Radiator Cap/Surge Tank Tester Adapter J 43244 Relay Puller Pliers J 43651 Water Pump Holding Tool

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Electrical Center Identification Views
• Circuit Testing
• Connector Repairs
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Underhood Electrical Center or Junction Block Replacement
• Instrument Cluster Description and Operation
• Indicator/Warning Message Description and Operation
• Water Pump Cleaning and Inspection
• Water Pump Cleaning and Inspection
• Coolant in Combustion Chamber
• Coolant in Combustion Chamber
• Coolant in Engine Oil
• Coolant in Engine Oil
• Testing for Intermittent Conditions and Poor Connections
• Engine Coolant Temperature Sensor Replacement
• Engine Coolant Temperature Sensor Replacement
• Engine Coolant Temperature Sensor Replacement
• Moving Parts and Hot Surfaces Warning
• Approximate Fluid Capacities (Except Hybrid)
• Approximate Fluid Capacities (Hybrid)
• Heater Core Replacement
• Engine Coolant/Water in Transmission
• Engine Coolant/Water in Transmission
• Engine Coolant/Water in Transmission
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Coolant in Combustion Chamber
• Coolant in Engine Oil
• Lower Engine Noise, Regardless of Engine Speed
• Lower Engine Noise, Regardless of Engine Speed
• Lower Engine Noise, Regardless of Engine Speed
• Lifting and Jacking the Vehicle
• Draining Fluids and Oil Filter Removal
• Engine Block Disassemble
• Engine Block Assemble
• Engine Block Assemble
• Draining Fluids and Oil Filter Removal
• Engine Block Assemble
• Fastener Caution
• Engine Control Module Replacement (LE5)
• Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection
• Transmission Fluid Level and Condition Check
• Transmission Fluid Level and Condition Check
• Battery Tray Replacement (LAT)
• Adhesives, Fluids, Lubricants, and Sealers
• Fuel Injector Sight Shield Replacement
• Drive Belt Idler Pulley Replacement
• Power Steering Pump Replacement (LZ4)
• Engine Splash Shield Replacement - Right Side
• Front Compartment Sight Shields Replacement
• Front Bumper Fascia Replacement
• DTC P0480 or P0481
• Thermostat Diagnosis
• Engine Overheating
• Loss of Coolant
• Engine Fails To Reach Normal Operating Temperature
• Flushing
• Cooling System Leak Testing
• Adhesives, Fluids, Lubricants, and Sealers