Engine Cooling System Chevrolet Impala IX

Fastener Tightening Specifications

Scheme 1

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Typical Scan Tool Data

FC Relay 1, and FC Relays 2 and 3 Ckt Open, Short Gnd, and Short Volts Test Status with component OFF

FC Relay 1, and FC Relays 2 and 3 Ckt Open, Short Gnd, and Short Volts Test Status with component ON

Circuit/System Description

The engine cooling fan system consists of a cooling fan assembly containing two electric cooling fans. The engine control module (ECM) uses two fan control circuits and a series of three relays to command 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.

Conditions for Running the DTC

1. The engine speed is greater than 400 RPM.
2. The ignition voltage is between 11-18 volts.
3. The relay control circuit is commanded from OFF to ON, or ON to OFF.
4. DTC P0480 and P0481 run continuously when the conditions above are met.

P0480

The commanded state of the ECM driver and the actual state of the control circuit do not match for greater than 5 seconds.

P0481

The commanded state of the ECM driver and the actual state of the control circuit do not match for greater than 5 seconds.

Action Taken When the DTC Sets

DTCs P0480 and P0481 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0480 and P0481 are Type B DTCs.

Diagnostic Aids

1. The ECM has the capability of providing command to the fan relays even when 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.
2. The scan tool cooling fan control function operates as follows: Fan Relay 1 operates both fans at a low speed Fan Relay 2 and 3 operates the right fan at a high speed Fan Relay 1, 2 and 3 operates both fans at a high speed
3. When disconnecting or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the correct orientation in the fuse block. Test the mating electrical terminals for tightness.

Reference Information

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Component Connector End Views -- Index

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Wiring Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#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

1. Engine operating, observe the DTC information with a scan tool. DTC P0480 or P0481 should not set.
2. Command the cooling fans ON and OFF at high speed while observing the scan tool circuit test status parameters listed below: FC Relay 1 Ckt Open, Short Gnd, and Short Volts Test Status FC Relay 2 and 3 Ckt Open, Short Gnd, and Short Volts Test Status The parameters should display OK or Not Run in each of the commanded states.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect all of the KR20 cooling fan relays.
2. Ignition ON, verify that a test lamp illuminates between ground and the relay coil ignition circuit terminal listed below: Fan 1 relay, terminal 86 Fan 2 relay, terminal 86 Fan 3 relay, terminal 85 If the test lamp does not illuminate, test the relay coil ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay coil ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
3. Connect the red lead of the DMM to a control circuit terminal listed below. Connect the black lead to ground. Set the DMM on the diode setting. The DMM should display OL. Fan 1 relay, terminal 85 Fan 2 relay, terminal 85 Fan 3 relay, terminal 86 If less than the specified range, test the appropriate relay coil control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
4. Command the cooling fan relay ON and OFF with a scan tool. The DMM should transition from OL when commanded OFF to less than 1 V when commanded ON. If the circuit voltage does not correspond to the specified values, test the control circuit for an open/high resistance or a short to voltage. If the circuit tests normal, replace the K20 ECM.
5. If all circuits test normal, test or replace the appropriate KR20 relay.

Component Testing

1. Ignition OFF, disconnect the KR20 cooling fan relay.
2. Test for 70-110 ohms between terminals 85 and 86. If not within the specified range, replace the KR20 cooling fan relay.
3. Measure the resistance between the terminals listed below. The DMM should display OL. 30 and 86 30 and 87 30 and 85 85 and 87 If less than the specified range, replace the KR20 cooling fan relay.
4. Test the Fan 2 relay for less than 2 ohms between terminals 30 and 87A. If greater than the specified range, replace the Fan 2 relay.
5. Connect a 20 A fused jumper wire between relay terminal 85 and B+. Connect a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the KR20 cooling fan relay.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accessory Wiring Junction Block Replacement»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
3. «Engine Coolant Fan Motor Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)
4. «Control Module References»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/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.

The engine is operating.

Conditions for Setting the DTC

The coolant temperature is warmer than 131°C (268°F) for greater than 2 seconds.

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

DTC P1258 is a Type A DTC.

Description and Operation

1. «Cooling Fan Description and Operation»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Instrument Cluster Description and Operation»(/chevrolet/impala/ix-2006-2016/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
3. «Indicator/Warning Message Description and Operation»(/chevrolet/impala/ix-2006-2016/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

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 «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Ensure that the vehicle has the correct engine coolant with correct concentration and is not old, contaminated, or contains additives. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
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»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Command the cooling fans ON and OFF with a scan tool. 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/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Test the thermostat for correct operation. Refer to «Thermostat Diagnosis»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Test the engine cooling system for overheating. Refer to «Engine Overheating»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/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/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-2-of-3__water-pump-cleaning-and-inspection) for the 3.9L engine.
4. Inspect the engine mechanical for worn/leaking/cracked cylinder heads or engine block. Refer to «Coolant in Combustion Chamber»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-diagnostic-information-and-procedures__coolant-in-combustion-chamber) for the 3.5L engine, or «Coolant in Combustion Chamber»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-diagnostic-information-and-procedures__coolant-in-combustion-chamber) for the 3.9L engine. Also, refer to «Coolant in Engine Oil»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-diagnostic-information-and-procedures__coolant-in-engine-oil) for the 3.5L engine, or «Coolant in Engine Oil»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-diagnostic-information-and-procedures__coolant-in-engine-oil) for the 3.9L 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/impala/ix-2006-2016/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.
2. Verify the customer concern.
3. Perform the Visual/Physical Inspection in this service information. 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.

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 ECM grounds are clean, tight, and correctly located. Refer to «Master Electrical Component List»(/chevrolet/impala/ix-2006-2016/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-master-electrical-component-list) and «Component Connector End Views»(/chevrolet/impala/ix-2006-2016/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-1-2-shift-solenoid-through-door-lock) .
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. Refer to «Checking Aftermarket Accessories»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
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/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Cooling Fan Inoperative»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)
3. «Coolant Heater Inoperative»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)
4. «Engine Overheating»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating)
5. «Loss of Coolant»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant)
6. «Thermostat Diagnosis»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)
7. «Engine Fails To Reach Normal Operating Temperature»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system__engine-fails-to-reach-normal-operating)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine cooling fan system consists of a cooling fan assembly containing two electric cooling fans. The engine control module (ECM) uses two fan control circuits and a series of three relays to command 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.

When disconnecting or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the correct orientation in the fuse block. Test the mating electrical terminals for tightness.

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Component Connector End Views -- Index

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Wiring Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#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

1. Verify that the following DTCs are not set: P0480, P0481. If any of the DTCs are set, refer to «DTC P0480 or P0481»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Ignition ON, observe the scan tool FC Relay 1 and FC Relay 2 and 3 Command parameters. The parameters should display OFF.
3. Ignition ON, observe that the engine cooling fans are not ON.

Note. The following tests must be performed on each cooling fan relay.

1. Ignition OFF, disconnect each KR20 cooling fan relay one at a time.
2. Ignition ON, observe that both fans are now OFF. If the fans are ON, test for a short to voltage in the relay controlled output circuit of the appropriate cooling fan. If the fans are OFF, test or replace the appropriate KR20 cooling fan relay.

1. Ignition OFF, disconnect the KR20 cooling fan relay.
2. Test for 70-110 ohms between terminals 85 and 86. If not within the specified range, replace the KR20 cooling fan relay.
3. Measure the resistance between the terminals listed below. The DMM should display OL. 30 and 86 30 and 87 30 and 85 85 and 87 If less than the specified range, replace the KR20 cooling fan relay.
4. Test the Fan 2 relay for less than 2 ohms between terminals 30 and 87A. If greater than the specified range, replace the Fan 2 relay.
5. Connect a 20 A fused jumper wire between relay terminal 85 and B+. Connect a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the KR20 cooling fan relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accessory Wiring Junction Block Replacement»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine cooling fan system consists of a cooling fan assembly containing two electric cooling fans. The engine control module (ECM) uses two fan control circuits and a series of three relays to command 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.

1. The ECM has the capability of providing command to the fan relays even when 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.
2. The scan tool cooling fan control function operates as follows: Fan Relay 1 operates both fans at a low speed Fan Relay 2 and 3 operates the right fan at a high speed Fan Relay 1, 2 and 3 operates both fans at a high speed
3. When disconnecting or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the correct orientation in the fuse block. Test the mating electrical terminals for tightness.

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Component Connector End Views -- Index

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Wiring Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#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

1. Ignition ON, observe the DTC information with a scan tool. Verify DTC P0480 or P0481 is not set. If a DTC is set, refer to «DTC P0480 or P0481»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Ignition ON, command the appropriate fan relay ON and OFF with a scan tool. Verify that the fans turn ON and OFF when changing between the commanded states.

1. Ignition OFF, disconnect all of the KR20 cooling fan relays.
2. Connect a 30 A fused jumper between the Fan 2 relay switch circuit terminal 30 and the ground circuit terminal 87.
3. Ignition ON, verify that a test lamp illuminates between ground and the relay switched B+ circuit terminal listed below: Fan 1 relay terminal 30 Fan 3 relay terminal 87 If the test lamp does not illuminate, test the appropriate relay switch B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay switch B+ circuit fuse is open, test the relay controlled output circuit for a short to ground. If the circuit tests normal, test or replace the appropriate G10 cooling fan motor.
4. Connect a 30 A fused jumper between the KR20 cooling fan relay circuit terminals listed below. Verify the appropriate fan is activated. Fan 3 relay, terminals 87 and 30 Fan 1 relay, terminals 30 and 87 If the corresponding cooling fan does not activate, test the relay controlled output circuit and the cooling fan ground circuit for an open/high resistance. If the circuits tests normal, replace the appropriate G10 cooling fan motor. If the corresponding cooling fan activates, replace the appropriate KR20 cooling fan relay.
5. Remove the jumper wire from the fan 2 relay cavity.
6. Install the Fan 2 relay. Verify both fans activate at low speed. If both fans do not activate, test the relay controlled output circuit terminal 87A of the Fan 2 relay for a short to ground or an open/high resistance.
7. If the circuits test normal, test or replace the Fan 2 relay.

1. Ignition OFF, disconnect the KR20 cooling fan relay.
2. Test for 70-110 ohms between terminals 85 and 86. If not within the specified range, replace the KR20 cooling fan relay.
3. Measure the resistance between the terminals listed below. The DMM should display OL. 30 and 86 30 and 87 30 and 85 85 and 87 If less than the specified range, replace the KR20 cooling fan relay.
4. Test the Fan 2 relay for less than 2 ohms between terminals 30 and 87A. If greater than the specified range, replace the Fan 2 relay.
5. Connect a 20 A fused jumper wire between relay terminal 85 and B+. Connect a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the KR20 cooling fan relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accessory Wiring Junction Block Replacement»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
3. «Engine Coolant Fan Motor Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Overheating

Loss of Coolant

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/impala/ix-2006-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/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 -19°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/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Wiring Repairs»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#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 (LGD/LZE)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Coolant Heater Cord Replacement (LGD/LZE)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Fails To Reach Normal Operating Temperature

Special Tools

1. J 24460-01: Cooling System Pressure Tester
2. J 42401: Radiator Cap/Surge Tank Test Adapter

Test

1. Remove the pressure cap.
2. Wash the pressure cap sealing surface with water.
3. Use the J 24460-01: Cooling System Pressure Tester (1) with J 42401: Radiator Cap/Surge Tank Test Adapter (2) in order to test the pressure cap.
4. Test the pressure cap for the following conditions: Pressure release when the J 24460-01: Cooling System Pressure Tester exceeds the pressure rating of the pressure cap. 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
2. J 42401: Radiator Cap/Surge Tank Test Adapter

1. Remove the pressure cap.
2. Test the operation of the pressure cap. Refer to «Pressure Cap Testing»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Wash the pressure cap mating surface with water.
4. Use the J 24460-01: Cooling System Pressure Tester (1) with J 42401: Radiator Cap/Surge Tank Test Adapter (2) in order to apply pressure to the 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 Tester

Draining Procedure

1. Remove the coolant pressure cap.
2. Place a drain pan under the drain cock.
3. Open the radiator drain cock.
4. Drain the cooling system.
5. If a complete engine block drain is required, remove the coolant drain plugs from the engine block. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) .
6. Inspect the coolant.
7. 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/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Filling Procedure

1. Close the radiator drain cock.
2. If a complete engine block drain was required, install the coolant drain plugs to the engine block. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) .
3. Remove the vent cap from the top right side of the radiator.
4. Slowly fill the cooling system with a 50/50 coolant mixture until the coolant comes out of the radiator vent. Refer to «Approximate Fluid Capacities»(/chevrolet/impala/ix-2006-2016/remont/lubrication-system/#maintenance-and-lubrication__approximate-fluid-capacities) .
5. Install the vent cap to the top right side of the radiator.
6. Slowly fill the cooling system with a 50/50 coolant mixture until the coolant level is visible and stable at the fill neck.
7. Install the pressure cap loosely, threaded on about one turn.
8. Start the engine and raise the engine speed to 2500 RPM and hold it there for 40 seconds, then shut engine off.
9. Remove the pressure cap and fill the coolant system until the level is visible and stable.
10. Install the pressure cap loosely, threaded on about one turn.
11. Start the engine and raise the engine speed to 2500 RPM and hold it there for 30 seconds, then shut engine off.
12. Remove the pressure cap and radiator vent cap, fill the coolant system until the coolant comes out of the radiator vent.
13. Install the radiator vent cap.
14. Install the pressure cap loosely, threaded on about one turn.
15. Start the engine and raise the engine speed to 2500 RPM and hold it there for 20 seconds, then shut engine off.
16. Remove the pressure cap and fill the coolant system until the level is visible and stable.
17. Install the pressure cap, fully threaded on.
18. Fill the coolant recovery bottle to the indicator line, then add 400 milliliters (13.5 ounces) more.
19. Start the engine and run it above 2500 RPM until it is hot enough to open the thermostat, this will allow the trapped air to be purged from the engine.
20. Complete a series of three, 4 second-duration idles with 4 second-duration 3000 RPM cycles.
21. Turn the engine off and allow it to cool down to room temperature.
22. Fill the coolant recovery bottle to the indicator line.
23. Inspect the concentration of the engine coolant using the J 26568: Coolant and Battery Tester.
24. Rinse away any excess coolant from the engine and the engine compartment.

J 26568: Coolant and Battery Tester

1. Remove the coolant pressure cap.
2. Place a drain pan under the drain cock.
3. Open the radiator drain cock.
4. Drain the cooling system.
5. If a complete engine block drain is required, remove the coolant drain plugs from the engine block. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.5L engine or to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.9L engine.
6. Inspect the coolant.
7. 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/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

1. Close the radiator drain cock.
2. If a complete engine block drain was required, install the coolant drain plugs to the engine block. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.5L engine or to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.9L engine.
3. Slowly fill the cooling system with a 50/50 coolant mixture until the coolant level is visible and stable. Refer to «Approximate Fluid Capacities»(/chevrolet/impala/ix-2006-2016/remont/lubrication-system/#maintenance-and-lubrication__approximate-fluid-capacities) .
4. Install the pressure cap loosely (threaded on about one turn).
5. Start the engine and raise the engine speed to 2500 RPM and hold it there for 40 seconds, then shut engine off.
6. Remove the pressure cap and fill the coolant system until the level is visible and stable.
7. Install the pressure cap loosely (threaded on about one turn).
8. Start the engine and raise the engine speed to 2500 RPM and hold it there for 30 seconds, then shut engine off.
9. Remove the pressure cap and fill the coolant system until the level is visible and stable.
10. Install the pressure cap loosely (threaded on about one turn).
11. Start the engine and raise the engine speed to 2500 RPM and hold it there for 20 seconds, then shut engine off.
12. Remove the pressure cap and fill the coolant system until the level is visible and stable.
13. Install the pressure cap, fully threaded on.
14. Fill the coolant recovery bottle to the indicator line, then add 400 milliliters (13.5 ounces) more.
15. Start the engine and run it above 2500 RPM until it is hot enough to open the thermostat, this will allow the trapped air to be purged from the engine.
16. Complete a series of three, 4-second-duration idles with 4-second-duration 3000 RPM cycles.
17. Turn the engine off and allow it to cool down to room temperature.
18. Fill the coolant recovery bottle to the indicator line.
19. Inspect the concentration of the engine coolant using the J 1657924: Coolant and Battery Tester
20. Rinse away any excess coolant from the engine and the engine compartment.

1. J 26568: Coolant and Battery Tester
2. J 42401: Radiator Cap/Surge Tank Test Adapter
3. GE-47716: Vac N Fill Coolant Refill Tool

1. Remove the coolant pressure cap.
2. Place a drain pan under the drain cock.
3. Open the radiator drain cock.
4. Drain the cooling system.
5. If a complete engine block drain is required, remove the coolant drain plugs from the engine block. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.5L engine or to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.9L engine.
6. Inspect the coolant.
7. 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/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Vac-N-Fill Procedure

1. If a complete engine block drain was required, install the coolant drain plugs to the engine block. Refer to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.5L engine or to «Draining Fluids and Oil Filter Removal»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-off-vehicle-1-of-3__draining-fluids-and-oil-filter-removal) for the 3.9L engine.
2. Install the J 42401: Radiator Cap/Surge Tank Test Adapter to the coolant fill port.
3. Attach the Vac N Fill cap to the J 42401: Radiator Cap/Surge Tank Test Adapter.
4. Attach the vacuum gauge assembly to the Vac N Fill cap.
5. Attach the fill hose to the barb fitting on the vacuum gauge assembly. Ensure that the valve is closed.
6. Pour the coolant mixture into the graduated reservoir.
7. Place the fill hose in the graduated reservoir.
8. Install the vacuum tank on the graduated reservoir with the fill hose routed through the cut-out area in the vacuum tank.
9. Attach the venturi assembly to the vacuum tank.
10. Attach a shop air hose to the venturi assembly. Ensure the valve on the venturi assembly is closed.
11. Attach the vacuum hose to the vacuum gauge assembly and the vacuum tank.
12. Open the valve on the venturi assembly. The vacuum gauge will begin to rise and a hissing noise will be present.
13. 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.
14. 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.
15. To aid in the fill process, position the graduated reservoir above the coolant fill port.
16. Close the valve on the venturi assembly.
17. 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/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
18. Open the valve on the vacuum gauge assembly. The vacuum gauge will drop as coolant is drawn into the system.
19. Once the vacuum gauge reaches zero, close the valve on the vacuum gauge assembly and repeat steps 11-17.
20. Detach the Vac N Fill cap from the J 42401: Radiator Cap/Surge Tank Test Adapter.
21. Remove the J 42401: Radiator Cap/Surge Tank Test Adapter from the coolant fill port.
22. Add coolant to the system as necessary.
23. Inspect the concentration of the coolant mixture using the J 26568 . See «Special Tools»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
24. Detach the vacuum hose from the vacuum gauge assembly.
25. Attach the extraction hose to the vacuum hose.
26. Open the valve on the venturi assembly to start a vacuum draw.
27. Use the extraction hose to draw out coolant to the proper level.
28. Fill the coolant recovery bottle to the indicator line, then add 400 milliliters (13.5 ounces) more.
29. Install the coolant pressure cap.
30. 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.
31. Start the engine and run it above 2500 RPM until it is hot enough to open the thermostat, this will allow the trapped air to be purged from the engine.
32. Turn the engine off and allow it to cool down to room temperature.
33. Fill the coolant recovery bottle to the indicator line.

Flushing

Note. Do not use a chemical flush.

Store used coolant in a properly labeled container. Do not pour used coolant down a drain. Ethylene glycol antifreeze is a very toxic chemical. Do not dispose of coolant into the sewer system or ground water. This is illegal and ecologically unsound.

Various methods and equipment can be used to flush the cooling system. If special equipment is used, such as a back flusher, follow the manufacturer's instruction.

When the cooling system becomes contaminated, the cooling system should be flushed thoroughly to remove the contaminants before the engine is seriously damaged.

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the coolant recovery reservoir. Refer to «Coolant Recovery Reservoir Replacement (LZE, LGD)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Clean and flush the coolant recovery reservoir with clean, drinkable water.
4. Install the coolant recovery reservoir. Refer to «Coolant Recovery Reservoir Replacement (LZE, LGD)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Follow the drain and fill procedure using only clean, drinkable water. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Run the engine for 20 minutes.
7. Stop the engine.
8. Drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
9. Repeat the procedure if necessary, until the fluid is nearly colorless.
10. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/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.

Removal Procedure

1. Reposition the reservoir hose clamp (1).
2. Remove the reservoir hose from the radiator overflow neck.
3. Remove the coolant recovery reservoir nuts (2) from the shock tower studs.
4. Remove the coolant recovery reservoir (3) from the lower retainer and the shock tower studs.
5. Drain the coolant from the recovery reservoir in to a clean container.

Installation Procedure

1. Install the coolant recovery reservoir (3) onto the lower retainer and the shock tower studs.
2. Install the coolant recovery reservoir nuts (2) to the shock tower studs and tighten to 3.3 N.m (29 lb in).
3. Lubricate the reservoir hose with clean water. Route the hose to the radiator overflow neck fitting.
4. Install the coolant reservoir hose (1) to the overflow neck fitting.
5. Install the reservoir hose and clamp (1), with the clamp tabs at the 11 o'clock position, to the radiator overflow fitting on the radiator filler neck. The hose end must be flush against the radiator filler neck. Seat the clamp squarely between the radiator filler neck and the flared end of the fitting.
6. Fill the coolant recovery reservoir to the proper level.

J 38185: Hose Clamp Pliers

1. Partially drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Use J 38185: Hose Clamp Pliers in order to reposition the hose clamp from the radiator.
3. Remove the inlet hose from the radiator.
4. Use J 38185: Hose Clamp Pliers in order to reposition the hose clamp from the engine outlet pipe.
5. Remove the radiator inlet hose from the engine outlet pipe and the vehicle.

1. Install the radiator inlet hose to the engine outlet pipe.
2. Use J 38185: Hose Clamp Pliers in order to reposition and install the hose clamp to the engine outlet pipe.
3. Install the inlet hose to the radiator.
4. Use J 38185: Hose Clamp Pliers in order to reposition and install the hose clamp to the radiator.
5. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .

J 38185: Hose Clamp Pliers

1. Partially drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Use J 38185: Hose Clamp Pliers in order to reposition the hose clamp from the radiator.
3. Remove the outlet hose from the radiator.
4. Use J 38185: Hose Clamp Pliers in order to reposition the hose clamp from the thermostat housing.
5. Remove the radiator outlet hose from the thermostat housing and the vehicle.

1. Install the radiator outlet hose to the thermostat housing.
2. Use J 38185: Hose Clamp Pliers in order to reposition and install the hose clamp to the thermostat housing.
3. Install the outlet hose to the radiator.
4. Use J 38185: Hose Clamp Pliers in order to reposition and install the hose clamp to the radiator.
5. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Using a bent-tip screwdriver or equivalent, pull on one of the open ends of the retaining ring in order to rotate the retaining ring.
2. Rotate the retaining ring around the quick connector until the retaining ring is out of position and can be completely removed.
3. Remove the engine oil cooler line from the quick connector fitting. Pull the lines straight out from the connector.
4. Clean all of the components in a suitable solvent, and dry them with compressed air.
5. Inspect the fittings, the connectors, the cooler lines, and the cooler for damage, distortion, or restriction. Replace parts as necessary.

1. Install the retaining ring into each quick connector fitting.
2. Hook one of the open ends of the retaining ring in one of the slots in the quick connector.
3. Rotate the retaining ring around the connector until the retaining ring is positioned with all 3 ears through the 3 slots.
4. Ensure the 3 retaining ring ears can be seen from the inside of the connector and the retaining ring can move freely in the slots.
5. Install the engine oil cooler line into the quick connector fitting. Pull back on the engine oil cooler lines to ensure a proper connection.
6. Inspect and fill the engine oil to the proper level.

1. Remove the right engine splash shield. Refer to «Engine Splash Shield Replacement (Right)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) or «Engine Splash Shield Replacement (Left)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) .
2. Remove the lower air baffle. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the support clip from the engine oil cooler lines.
4. Remove the engine oil cooler lines from the engine oil cooler. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Remove the engine oil cooler lines from the engine oil filter adapter. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Remove the engine oil cooler lines from the vehicle.

1. Install the engine oil cooler lines to the vehicle.
2. Install the engine oil cooler lines to the engine oil cooler. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Install the engine oil cooler lines to the engine oil filter adapter. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Install the engine oil cooler line support clip to the engine oil cooler lines.
5. Install the right engine splash shield. Refer to «Engine Splash Shield Replacement (Right)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) or «Engine Splash Shield Replacement (Left)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Install the lower air baffle. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Add the proper amount of engine oil.

1. Remove the upper air baffle. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the right engine splash shield. Refer to «Engine Splash Shield Replacement (Right)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) or «Engine Splash Shield Replacement (Left)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) .
3. Remove the lower air baffle. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Remove the support clip from the engine oil cooler lines.
5. Reposition the hose clamps on the power steering cooler lines.
6. Remove the power steering oil cooler lines from the power steering cooler.
7. Remove the engine oil cooler lines from the engine oil cooler. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Remove the upper bolt (1) from the engine oil cooler/power steering cooler.
9. Remove the lower bolts (2) from the engine oil cooler/power steering cooler.
10. Remove the engine oil cooler/power steering cooler from the vehicle.

1. Install the engine oil cooler/power steering cooler to the vehicle.
2. Install the upper bolt (1) to the engine oil cooler/power steering cooler bracket and tighten to 2 N.m (18 lb in).
3. Install the lower bolts (2) to the engine oil cooler/power steering cooler bracket and tighten to 2 N.m (18 lb in).
4. Install the engine oil cooler lines to the engine oil cooler. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Install the power steering oil cooler lines to the power steering cooler.
6. Reposition the hose clamps on the power steering cooler lines.
7. Install the support clip to the engine oil cooler lines.
8. Install the right engine splash shield. Refer to «Engine Splash Shield Replacement (Right)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) or «Engine Splash Shield Replacement (Left)»(/chevrolet/impala/ix-2006-2016/remont/frames-subframes-crossmembers/#frame-and-underbody) .
9. Install the lower air baffle. Refer to «Radiator Air Lower Baffle and Deflector Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
10. Install the upper air baffle. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
11. Add the proper amount of engine oil and power steering fluid.
12. Bleed the power steering system. Refer to «Power Steering System Bleeding»(/chevrolet/impala/ix-2006-2016/remont/manual-power-steering/#power-steering-system) .

GE-47827: Socket

1. Remove the fan shroud assembly from the vehicle. Refer to «Engine Coolant Fan Shroud Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Using GE-47827: Socket turn the fan motor drive plate in the opposite direction of the arrow on the fan blade until the motor drive plate disengages from the fan blade.
3. Remove and discard the fan blade.
4. Center punch each of the rivets (1) from the rear of the motor.
5. Drill the head of the rivets (1) from the fan motor using a 6.35 mm (0.25 in) drill bit.
6. Tap the rivets out of the fan shroud.
7. Remove the fan motor from the fan shroud.
8. Remove the tape covering the entry points from the fan motor.

1. Install the engine cooling fan motor to the fan shroud.
2. Install the cooling fan motor bolts.
3. Install the cooling fan motor nuts and tighten to 6 N.m (53 lb in).
4. Install the new engine cooling fan blade.
5. Using the GE-47827: Socket turn the fan motor drive plate in the same direction of the arrow on the fan blade until the fan motor drive plate engages to the fan blade. Full engagement is attained when the motor drive plate fully occupies the three slots in the face of the fan blade.
6. Rotate the cooling fan blade to ensure proper rotation.
7. Install the fan shroud assembly to the vehicle. Refer to «Engine Coolant Fan Shroud Replacement»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) or «Air Cleaner Outlet Duct Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-39l-repair-instructions) .
3. Reposition the radiator outlet hose clamp at the thermostat housing.
4. Remove the radiator outlet hose from the thermostat housing (3.5L shown in illustration, 3.9L similar).
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. Tighten: Tighten the bolt/stud to 10 N.m (89 lb in).
3. Install the radiator outlet hose to the thermostat housing (3.5L shown in illustration, 3.9L similar).
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/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) or «Air Cleaner Outlet Duct Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-39l-repair-instructions) .
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/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 (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) or «Air Cleaner Outlet Duct Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-39l-repair-instructions) .
3. Reposition the radiator outlet hose clamp at the thermostat housing.
4. Remove the radiator outlet hose from the thermostat housing (3.5L shown in illustration, 3.9L similar).
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. Tighten: Tighten the bolt/stud to 10 N.m (89 lb in).
4. Install the radiator outlet hose to the thermostat housing (3.5L shown in illustration, 3.9L similar).
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/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) or «Air Cleaner Outlet Duct Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-39l-repair-instructions) .
7. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Inspect the system for leaks.

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine, or «Intake Manifold Cover Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.
2. Remove the generator. Refer to «Generator Replacement (LGD/LZE)»(/chevrolet/impala/ix-2006-2016/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the drive belt idler pulleys. Refer to «Drive Belt Idler Pulley Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine, or «Drive Belt Idler Pulley Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.
4. Remove the power steering pump. Refer to «Power Steering Pump Replacement (LZ4/LZE/LZ9)»(/chevrolet/impala/ix-2006-2016/remont/manual-power-steering/#power-steering-system) .
5. Reposition the coolant recovery reservoir hose clamp at the fill tube fitting.
6. Remove the coolant recovery reservoir hose from the fill tube fitting. Position the hose out of the way.
7. Reposition the radiator inlet hose clamp at the crossover pipe (3.5L shown in illustration, 3.9L similar).
8. Remove the radiator inlet hose from the crossover pipe.
9. Reposition the thermal bypass hose clamp at the crossover pipe.
10. Remove the thermal bypass hose from the crossover pipe.
11. Remove the coolant crossover pipe bolts (2, 3, 4).
12. Remove the coolant crossover pipe.

1. Position the coolant crossover pipe to the cylinder heads.
2. Install the coolant crossover pipe bolts (2, 3, 4). Tighten: Tighten the bolts 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 (3.5L shown in illustration, 3.9L similar).
6. Position the radiator inlet hose clamp at the crossover pipe.
7. Install the coolant recovery reservoir hose to the fill tube fitting.
8. Position the coolant recovery reservoir hose clamp at the fill tube fitting.
9. Install the power steering pump. Refer to «Power Steering Pump Replacement (LZ4/LZE/LZ9)»(/chevrolet/impala/ix-2006-2016/remont/manual-power-steering/#power-steering-system) .
10. Install the drive belt idler pulleys. Refer to «Drive Belt Idler Pulley Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine, or «Drive Belt Idler Pulley Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.
11. Install the generator. Refer to «Generator Replacement (LGD/LZE)»(/chevrolet/impala/ix-2006-2016/remont/charging-system/#battery-charging-system-and-starting-system) .
12. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine, or «Intake Manifold Cover Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/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/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine, or «Drive Belt Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.
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. Tighten: Tighten the bolts to 15 N.m (11 lb ft).
3. Install the water pump pulley and bolts.
4. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine, or «Drive Belt Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.
5. Tighten the water pump pulley bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Inspect for leaks.

Scheme 2

Scheme 3

J 38185: Hose Clamp Pliers

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (LGD/LZE)»(/chevrolet/impala/ix-2006-2016/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) for the 3.5L engine or «Air Cleaner Assembly Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-39l-repair-instructions) for the 3.9L engine.
3. Drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Remove the engine mount struts. Refer to «Engine Mount Strut Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine or «Engine Mount Strut Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.
5. Use J 38185: Hose Clamp Pliers to reposition the upper radiator hose clamp from the radiator.
6. Remove the upper radiator hose from the radiator.
7. Remove the powertrain control module (PCM) harness clip from the fan shroud.
8. Remove the condenser tubes bracket bolt from the fan shroud.
9. Remove the bolt that connects the fan shroud to the condenser hold down bracket.
10. Remove the condenser hold down bracket from the radiator and condenser.
11. Remove the cooling fan shroud bolts.
12. Remove the coolant reservoir hose from the fan shroud LS4 only.
13. Remove the radiator vent hose from the right upper radiator tank LS4 only.
14. Remove the radiator upper support brackets and bolts that connect to the fan shroud.
15. Disconnect the engine cooling fan motors electrical connectors.
16. Remove the cooling fan motors electrical harness from the fan shroud clips.
17. Remove the cooling fan shroud.
18. Use J 38185: Hose Clamp Pliers to reposition the lower radiator hose clamp from the radiator.
19. Remove the lower radiator hose from the radiator.
20. Disconnect the transaxle oil cooler pipes from the radiator. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(/chevrolet/impala/ix-2006-2016/remont/automatic-trans/#automatic-transmission-4t65-e-repair-instructions-on-vehicle) .
21. Tilt the top of the radiator rearward.
22. Lift the condenser from the mounting tabs on the radiator (2). Position the condenser aside.
23. Remove the radiator.

1. Install the radiator to the lower mounts.
2. Install the condenser to the mounting tabs on the radiator (2).
3. Install the condenser hold down bracket (1) to the radiator and condenser.
4. Install the lower radiator hose to the radiator.
5. Use J 38185: Hose Clamp Pliers to install the lower radiator hose clamp to the radiator.
6. Install the cooling fan shroud.
7. Install the condenser tubes bracket bolt to the fan shroud and tighten to 10 N.m (89 lb in).
8. Install the cooling fan motors electrical harness to the fan shroud clips.
9. Connect the engine cooling fan motors electrical connectors.
10. Install the cooling fan shroud bolts and tighten to 10 N.m (89 lb in).
11. Connect the transaxle oil cooler pipes to the radiator. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(/chevrolet/impala/ix-2006-2016/remont/automatic-trans/#automatic-transmission-4t65-e-repair-instructions-on-vehicle) .
12. Install the radiator upper support brackets and bolts that connect to the fan shroud and tighten to 6 N.m (53 lb in).
13. Install the bolt that connects the fan shroud to the condenser hold down bracket and tighten to 6 N.m (53 lb in).
14. Install the PCM harness clip on to the fan shroud.
15. Install the upper radiator hose to the radiator.
16. Use J 38185: Hose Clamp Pliers to install the upper radiator hose clamp to the radiator.
17. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) for the 3.5L engine or «Air Cleaner Assembly Replacement»(/chevrolet/impala/ix-2006-2016/remont/testing-diagnostics/#engine-controls-and-fuel-39l-repair-instructions) for the 3.9L engine.
18. Install the coolant reservoir hose to the fan shroud.
19. Install the radiator vent hose to the right upper radiator tank and fill neck.
20. Install the engine mount struts. Refer to «Engine Mount Strut Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-35l-repair-instructions-on-vehicle) for the 3.5L engine or «Engine Mount Strut Replacement»(/chevrolet/impala/ix-2006-2016/remont/mechanical/#engine-mechanical-39l-repair-instructions-on-vehicle) for the 3.9L engine.
21. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
22. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (LGD/LZE)»(/chevrolet/impala/ix-2006-2016/remont/charging-system/#battery-charging-system-and-starting-system) .
23. Adjust the transaxle fluid level.

Scheme 4

Scheme 5

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Disconnect the engine coolant heater cord (2) from the engine coolant heater.
3. Remove the engine coolant heater.
4. Clean the engine coolant heater opening.

1. Apply sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the threads of the engine coolant heater, if necessary.
2. Install the engine coolant heater. Tighten: Tighten the coolant heater to 60 N.m (44 lb ft).
3. Connect the engine coolant heater cord (2) to the engine coolant heater.
4. Lower the vehicle.
5. Fill the cooling system. Refer to «Cooling System Draining and Filling (9C1, 9C3 Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD Static Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (LZE, LGD GE47716 Fill)»(/chevrolet/impala/ix-2006-2016/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Inspect for leaks.

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/impala/ix-2006-2016/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Disconnect the engine coolant heater cord (2) from the engine coolant heater.
3. Remove the heater cord clip (3) from the engine block.
4. Lower the vehicle.
5. Remove the heater cord clips (4, 5) from the transaxle.
6. Remove the heater cord clamp from the engine harness.
7. Cut the heater cord tape (1) at the diagonal brace and remove the cord.

1. Lay the heater cord into place.
2. Install the heater cord clamp to the engine harness.
3. Install the heater cord clips (4, 5) to the transaxle.
4. Raise and support the vehicle.
5. Install the heater cord clip (3) to the engine block.
6. Connect the engine coolant heater cord (2) to the engine coolant heater.
7. Lower the vehicle.
8. Gather any slack and install the heater cord tape (1) at the diagonal brace.

Scheme 6

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 receive positive voltage from the cooling fan relays which 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 Fan 1 Relay, 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 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 Series/Parallel relay, which is Fan 2 Relay, 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 grounds the high speed fan relay, which is Fan 3 Relay 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 speed fan relay coil is energized, the relay contacts close to provide battery positive voltage from the 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.

When the requests 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.

TEMP

1. The instrument panel cluster (IPC) illuminates the TEMP indicator when the powertrain control module (PCM) determines that the coolant temperature is more than 128°C (262°F). The IPC receives a discrete input from the PCM 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 coolant recovery reservoir 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.

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.

Cooling Cycle

Coolant is drawn from the radiator outlet to the thermostat. The flow of coolant will be stopped at the thermostat until the engine is warmed; while the thermostat is closed the water pump circulates coolant through the engine block and heater core. Coolant is returned to the water pump through the engine bypass and the heater core outlet hose. This provides the passenger compartment with heat and defrost.

After the thermostat opens, the coolant is pumped through the water pump outlet and into the engine block and heater core. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.

The coolant is then forced 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 it absorbs additional heat.

From the cylinder heads, the coolant is then forced into the radiator where it is cooled and the coolant cycle is completed.

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

The cooling systems 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.

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 end 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.

Engine Oil Cooler

The engine oil cooler is a heat exchanger which is located external to the radiator. The oil temperature is cooled by the air passing through the oil cooler fins. The oil pump pumps the oil through the feed line to the oil cooler. The oil flows through the cooler where the air absorbs heat from the oil. The oil is then pumped through the cooler return line to the oil filter and returns to the main oil passage.

Transmission Oil Cooler - Internal

The transmission oil cooler is a heat exchanger that is located inside one of the radiator end tanks. The transmission fluid temperature is regulated by the temperature of the engine coolant in the radiator. The oil pump pumps the fluid through the transmission oil cooler feed line to the oil cooler. The fluid flows through the cooler where the engine coolant absorbs heat from the fluid. The fluid is then pumped through the oil cooler return line back to the transmission.

Transmission Oil Cooler - External

The transmission oil cooler is a heat exchanger that is located external to the radiator. Air passing through the oil cooler fins cools the transmission fluid temperature. Within the transmission system, the oil pump pumps the fluid through the feed line to the oil cooler. The fluid then flows through the cooler where air absorbs heat from the fluid. The fluid is then pumped through the oil cooler return line back to the transmission.

Illustration Tool Number/ Description GE 47716 Vac N Fill Coolant Refill Tool GE 47827 Socket J 24460-01 Cooling System Pressure Tester J 26568 Coolant and Battery Fluid Tester J 35616 Connector Test Adapter Kit J 38185 Hose Clamp Pliers J 42220 Universal 12V Leak Detection Lamp J 42401 Radiator Cap/Surge Tank Test Adapter J 43244 Relay Puller Pliers

Scheme 7

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Scheme 13

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views -- Index
• Circuit Testing
• Connector Repairs
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Accessory Wiring Junction Block Replacement
• Instrument Cluster Description and Operation
• Water Pump Cleaning and Inspection
• Coolant in Combustion Chamber
• Coolant in Engine Oil
• Master Electrical Component List
• Component Connector End Views
• Checking Aftermarket Accessories
• Testing for Intermittent Conditions and Poor Connections
• Engine Coolant Temperature Sensor Replacement
• Engine Coolant Temperature Sensor Replacement
• Diagnostic Starting Point - Vehicle
• Moving Parts and Hot Surfaces Warning
• Approximate Fluid Capacities
• Heater Core Replacement
• Engine Coolant/Water in Transmission
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Lower Engine Noise, Regardless of Engine Speed
• Lower Engine Noise, Regardless of Engine Speed
• Cylinder Leakage Test
• Cylinder Leakage Test
• Draining Fluids and Oil Filter Removal
• Fastener Caution
• Engine Splash Shield Replacement (Right)
• Power Steering System Bleeding
• Intake Manifold Cover Replacement
• Intake Manifold Cover Replacement
• Generator Replacement (LGD/LZE)
• Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection
• Lifting and Jacking the Vehicle
• DTC P0480 or P0481
• Engine Overheating
• Loss of Coolant
• Engine Fails To Reach Normal Operating Temperature
• Flushing