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Engine Cooling System Buick Enclave I

Cooling System (Mechanical) 15 illustrations ~7579 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Thermostat Housing Bolts10 N.m89 lb in
Thermostat Housing Bracket Bolt50 N.m37 lb ft
Water Outlet Housing Bolts10 N.m89 lb in
Water Pump Bolts12 N.m106 lb in
Water Pump Pulley Bolts10 N.m89 lb in

Fastener Tightening Specifications

Scheme 1

Scheme 1: Engine Cooling System
Scheme 1: Engine Cooling System

Diagnostic Code Index

DTCDescription
DTC P0480, P0481, P0691, P0692, P0693, or P0694DTC P0480 Cooling Fan Relay 1 Control Circuit DTC P0481 Cooling Fan Relays 2 and 3 Control Circuit DTC P0691 Cooling Fan Relay 1 Control Circuit Low Voltage DTC P0692 Cooling Fan Relay 1 Control Circuit High Voltage DTC P0693 Cooling Fan Relays 2 and 3 Control Circuit Low Voltage DTC P0694 Cooling Fan Relays 2 and 3 Control Circuit High Voltage
DTC P1258DTC P1258 Engine Coolant Overtemperature - Protection Mode Active

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Relay Coil IgnitionP0691, P0693P0480, P0481
Relay Switch B+ Supply11
Cooling Fan-Left High Speed Relay ControlP0691P0480P0692
Cooling Fan-Right High Speed and Speed Control Relay ControlP0693P0481P0694
Relay Controlled Output112
1. Fans inoperative without a DTC. 2. Fans always ON without a DTC.

Typical Scan Tool Data

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Component Commanded OFF Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Short Gnd test and Not Run for Short Volts test Component ON - Not Run for Open/Short Gnd test and OK for Short Volts test
Ignition VoltageFaultFault
Cooling Fan-Left High Speed Relay ControlFaultFault
Cooling Fan-Right High Speed and Speed Control Relay ControlFaultFaultNot Run

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

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Component Commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Short Gnd test and Not Run for Short Volts test Component ON - Not Run for Open/Short Gnd test and OK for Short Volts test
Ignition VoltageNot RunNot Run
Cooling Fan-Left High Speed Relay ControlNot RunNot RunFault
Cooling Fan-Right High Speed and Speed Control Relay ControlNot RunNot RunFault

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

In low speed operation, the ECM applies ground to the coil side of the cooling-left high speed relay. This energizes the coil and applies voltage directly to the left cooling fan through the switch side of the relay. The left fan is connected in series to the right cooling fan through the de-energized speed control relay. The series circuit operates both fans at low speed.

In high speed operation, the ECM applies a ground to the coil side of the cooling-left high speed relay, the speed control relay, and the cooling fan-right high speed relay. When energized, the right high speed relay applies voltage directly to the right cooling fan through the switch side of the relay. Simultaneously, the left high speed relay and the speed control relay provide ignition voltage and a direct path to ground for the left cooling fan. With both fans connected in a parallel circuit, each fan receives full voltage and operates at high speed.

Conditions for Running the DTC

  1. The ignition voltage is greater than 11 volts.
  2. The ECM driver transitions from ON to OFF or from OFF to ON.
  3. DTCs P0480, P0481, P0691, P0692, P0693, and P0694 run continuously when the conditions above are met.

Conditions for Setting the DTC

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, P0481, P0691, P0692, P0693, and P0694 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0480, P0481, P0691, P0692, P0693, and P0694 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

Reference Information

Schematic Reference

Connector End View Reference

  1. «COMPONENT CONNECTOR END VIEWS - INDEX»(/buick/enclave/i-2007-2013/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

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, P0481, P0691, P0692, P0693, or P0694 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: Cooling fan left high speed relay terminal 85 Cooling fan right high speed relay terminal 85 Cooling fan speed control relay terminal 86 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. Cooling fan left high speed relay terminal 86 Cooling fan right high speed relay terminal 86 Cooling fan speed control relay terminal 85 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 for 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 cooling relay.

Component Testing

  1. Ignition OFF, disconnect the cooling fan relay.
  2. Test for 200-240 ohms between terminals 85 and 86. If not within the specified range, replace the 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 relay.
  4. Test for less than 2 ohms between terminals 30 and 87A. If greater than the specified range, replace the relay.
  5. Install a 20 A fused jumper wire between relay terminal 85 and 12 volts. Install 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 relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Within an Electrical Center)»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  2. «Control Module References»(/buick/enclave/i-2007-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

  1. The engine is operating for greater than 30 seconds.
  2. DTC P1258 runs continuously once the conditions above have been met.

The ECM detects that engine 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 Operating Mode.
  3. The IP will illuminate the coolant temperature indicator lamp and the driver information center (DIC), if equipped, may display a message.
  4. If the protection mode is active and an ECT sensor DTC sets, the protection mode will remain active at the start of the next drive cycle until the ECT sensor DTC runs and passes.

DTC P1258 is a Type A DTC.

Schematic Reference

Connector End View Reference

Description and Operation

  1. «Cooling Fan Description and Operation»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system)
  2. «Instrument Cluster Description and Operation»(/buick/enclave/i-2007-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
  3. «Indicator/Warning Message Description and Operation»(/buick/enclave/i-2007-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

Electrical Information Reference

  1. «Circuit Testing»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Wiring Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Note. If DTC P0480, P0481, P0691, P0692, P0693, or P0694 is set, diagnose that DTC first.

  1. Observe the engine coolant level. The engine coolant level should be within the operating range. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. 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 (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. 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»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  4. Command the cooling fans ON and OFF, low and high speed. The engine cooling fans should turn ON and OFF with each command. If the cooling fans do not function as indicated, refer to «Cooling Fan Inoperative»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Test the thermostat for correct operation. Refer to «Thermostat Diagnosis»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) .
  2. Test the engine cooling system for overheating. Refer to «Engine Overheating»(/buick/enclave/i-2007-2013/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»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-repair-instructions-off-vehicle) .
  4. Inspect the engine mechanical for worn, leaking, cracked cylinder heads or engine block. Refer to «Coolant in Engine Oil»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-diagnostic-information-and-procedures__coolant-in-engine-oil) .

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»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information) and verify all of the following items: Engine control module (ECM) and indicator lamp are operating correctly. There are no diagnostic trouble codes (DTCs) stored. Scan tool data is within a normal operating range.
  2. Verify the customer concern.
  3. Perform the Visual/Physical Inspection below. 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 entire cooling system operation in order to familiarize yourself with the system functions. Refer to Cooling Fan Description and Operation , and Cooling System Description and Operation .

Visual/Physical Inspection

CAUTIONUse the connector test adapter kit EL-35616-F for any test that requires probing the following items: The control module harness connectors The electrical center fuse/relay cavities The component terminals The component harness connector Using this kit will prevent damage caused by the improper probing of connector terminals.

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

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

  1. Water intrusion in connectors, terminals, or components
  2. Poor 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 are routed too tight, or chaffed circuits
  6. High or low ambient temperatures
  7. High or low engine coolant temperatures
  8. High underhood temperatures
  9. Heat build up in components or circuits 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, or after factory add on accessories

If an intermittent is detected, 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. «Engine Cooling Fan Always On»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system)
  2. «Engine Cooling Fan Inoperative»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system)
  3. «Engine Overheating»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating)
  4. «Loss of Coolant»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant)
  5. «Thermostat Diagnosis»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis)
  6. «Engine Fails To Reach Normal Operating Temperature»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__engine-fails-to-reach-normal-operating)
  1. Perform the «Diagnostic System Check - Vehicle»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

In low speed operation, the ECM applies ground to the coil side of the cooling-left high speed relay. This energizes the coil and applies voltage directly to the left cooling fan through the switch side of the relay. The left fan is connected in series to the right cooling fan through the de-energized speed control relay. The series circuit operates both fans at low speed.

In high speed operation, the ECM applies a ground to the coil side of the cooling-left high speed relay, the speed control relay, and the cooling fan-right high speed relay. When energized, the right high speed relay applies voltage directly to the right cooling fan through the switch side of the relay. Simultaneously, the left high speed relay and the speed control relay provide ignition voltage and a direct path to ground for the left cooling fan. With both fans connected in a parallel circuit, each fan receives full voltage and operates at high speed.

Schematic Reference

Connector End View Reference

  1. «COMPONENT CONNECTOR END VIEWS - INDEX»(/buick/enclave/i-2007-2013/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Wiring Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that DTCs P0480, P0481, P0691, P0692, P0693 and P0694 are not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
  2. Ignition ON, observe the scan tool Cooling Fan Relay 1 and Cooling Fan Relays 2 and 3 Command parameters. The parameters should display OFF.
  3. Ignition ON, observe that the fans are not activated.
  1. Ignition OFF, disconnect the cooling-left high speed relay.
  2. Ignition ON, observe that both fans are OFF. If both fans are OFF, test or replace the cooling fan -left high speed relay. If both fans continue to operate, test the left high speed relay controlled output circuit for a short to voltage. If the right fan is activated, perform the next test.
  3. Ignition OFF, disconnect the cooling fan-right high speed relay.
  4. Ignition ON, observe that the right fan is OFF. If the right fan is activated, test the right high speed relay controlled output circuit for a short to voltage.
  5. If the circuits test normal, test or replace the cooling fan-right high speed relay.
  1. Ignition OFF, disconnect the cooling fan relay.
  2. Test for 200-240 ohms between terminals 85 and 86. If not within the specified range, replace the 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 relay.
  4. Test for less than 2 ohms between terminals 30 and 87A. If greater than the specified range, replace the relay.
  5. Install a 20 A fused jumper wire between relay terminal 85 and 12 volts. Install 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 relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Underhood Electrical Center or Junction Block Replacement»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  2. «Relay Replacement (Within an Electrical Center)»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  1. Perform the «Diagnostic System Check - Vehicle»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

In low speed operation, the ECM applies ground to the coil side of the cooling-left high speed relay. This energizes the coil and applies voltage directly to the left cooling fan through the switch side of the relay. The left fan is connected in series to the right cooling fan through the de-energized speed control relay. The series circuit operates both fans at low speed.

In high speed operation, the ECM applies a ground to the coil side of the cooling-left high speed relay, the speed control relay, and the cooling fan-right high speed relay. When energized, the right high speed relay applies voltage directly to the right cooling fan through the switch side of the relay. Simultaneously, the left high speed relay and the speed control relay provide ignition voltage and a direct path to ground for the left cooling fan. With both fans connected in a parallel circuit, each fan receives full voltage and operates at high 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

Schematic Reference

Connector End View Reference

  1. «COMPONENT CONNECTOR END VIEWS - INDEX»(/buick/enclave/i-2007-2013/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that DTCs P0480, P0481, P0691, P0692, P0693 and P0694 are not set. If any cooling system DTCs are set, repair the DTC first. Refer to «DTC P0480, P0481, P0691, P0692, P0693, or P0694»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Ignition ON, command the cooling fans 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 the cooling fan relays.
  2. Connect a 30 A fused jumper between the relay switch circuit terminal 30 and the relay ground circuit terminal 87 at the speed control relay connector. This will complete the left side fan ground circuit. Leave this jumper in place for the remainder of this procedure.
  3. Ignition ON, verify that a test lamp illuminates between the relay switch B+ circuit terminal 30 and ground. 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 cooling fan.
  4. Connect a 40 A fused jumper between the relay switch B+ circuit terminal 30 and the relay controlled output circuit terminal 87. Verify the appropriate fan is activated If the appropriate fan does not activate, test the relay controlled output circuit for an open/high resistance. If the circuit tests normal, test the fan ground circuit for an open/high resistance. If the circuit tests normal, replace the appropriate cooling fan.
  5. Install the speed control relay. Verify both fans activate at low speed. If both fans do not activate, test the relay controlled output circuit terminal 87A of the speed control relay for a short to ground or an open/high resistance.
  6. If all circuits test normal, test or replace speed control the relay.
  1. Ignition OFF, disconnect the cooling fan relay.
  2. Test for 200-240 ohms between terminals 85 and 86. If not within the specified range, replace the 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 not the specified range, replace the relay.
  4. Test for less than 2 ohms between terminals 30 and 87A. If greater than the specified range, replace the relay.
  5. Install a 20 A fused jumper wire between relay terminal 85 and 12 volts. Install 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 relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Within an Electrical Center)»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  2. «Cooling Fan and Shroud Replacement»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Overheating

StepActionYesNo
DEFINITION: Either of the following conditions indicate a probable engine overheat condition. The engine temperature gauge is in the red (overheat) zone and/or the engine temperature indicator is ON. Hot engine coolant overflows from the coolant recovery reservoir and/or radiator cap onto the ground while the engine is running.
1Inspect and fill the cooling system, as necessary. Refer to Cooling System Draining and Filling (Static Fill) , Cooling System Draining and Filling (Vac N Fill) . Inspect the cooling system for leaks, as necessary. Repair the cooling system leaks, as necessary. Has the inspection/repair been performed?Go to Step 2
2Start the engine and allow the engine to run at approximately 1,200 RPM. Use the Scan Tool in order to verify the overheat condition. Does the Scan Tool verify the engine overheat condition?Go to Step 3Go to Diagnostic System Check - Vehicle
3Verify that the cooling fans are operating properly. Repair the cooling fan system, as necessary. Does the engine still overheat?Go to Step 4System OK
4Perform the following inspections: Inspect the radiator and the A/C condenser cooling fins for debris or any other obstruction. Inspect the drive belt system and the drive belt tensioner for proper operation in order to ensure that the coolant pump is rotating properly. Inspect for loose, damaged and/or missing air deflector(s). Check for a pinched or kinked cooling system hose. Repair the systems as necessary. Does the engine still overheat?Go to Step 5System OK
5Inspect the thermostat for proper operation. Refer to Thermostat Diagnosis . Is the thermostat operating properly?Go to Step 7Go to Step 6
6Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Does the engine still overheat?Go to Step 7System OK
7IMPORTANT: Excessive coolant freeze point protection MAY cause the coolant to boil at low temperatures. Inspect for the proper coolant concentration (mixture). Correct the coolant concentration as necessary. Remove the radiator cap. Start the engine and inspect for a constant flow of air bubbles in the engine coolant. Is there a constant flow of air bubbles in the engine coolant?Go to Step 8Go to Step 9
8The probable cause of the engine overheat is combustion chamber gasses leaking into the cooling system. This condition is usually caused by the following: A worn or damaged cylinder head gasket A worn or damaged cylinder head A worn and/or damaged engine block Verify this condition by inspecting the spark plug electrodes and porcelain surrounding the spark plug electrode for signs of coolant. Replace and/or repair the engine internal component(s), as necessary, in order to repair the engine internal coolant leak. Does the engine still overheat?Go to Step 1System OK
9The engine overheat may be caused by a cooling system blockage. Flush the cooling system. Refer to Flushing . Does the engine still overheat?Go to Step 10System OK
10IMPORTANT: It is unlikely that the water pump is the cause of the overheat condition. If NONE of the cooling system passages are restricted, replace the coolant pump. Refer to Water Pump Replacement .Does the engine still overheat?Go to Step 1System OK
IMPORTANT
Excessive coolant freeze point protection MAY cause the coolant to boil at low temperatures.
IMPORTANT
It is unlikely that the water pump is the cause of the overheat condition.

Engine Overheating

Loss of Coolant

StepActionYesNo
DEFINITION: The cooling system is losing coolant either internally or externally.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - Engine Cooling
2Repair any present DTCs. Refer to Diagnostic Starting Point - Vehicle . Is the action complete?Go to Step 3
3Inspect the coolant level. Is the coolant at the proper level?Go to Step 5Go to Step 4
4Fill the cooling system to the proper level. Refer to Cooling System Draining and Filling (Static Fill) , Cooling System Draining and Filling (Vac N Fill) . Is the action complete?Go to Step 5
5If the engine is suspected to have a coolant leak into the cylinder, the coolant can hydraulically lock the cylinder. Does the engine crankshaft rotate?Go to Step 6Go to Step 31
6Engine overheating can cause a loss of coolant. Is the engine overheating?Go to Step 32Go to Step 7
7Extended engine operation with a low coolant level can cause engine internal component failure. Is the engine knocking?Go to Step 34Go to Step 8
8Idle the engine at normal operating temperature. Inspect for heavy white smoke coming out of the exhaust pipe. Is a heavy white smoke present from the exhaust pipe?Go to Step 9Go to Step 10
9Coolant in the exhaust system creates a distinctive, burning coolant odor in the exhaust. Condensation in the exhaust system can cause an odorless white smoke during engine warm up. Does the white smoke have a burning coolant type odor?Go to Step 33Go to Step 10
10With the engine idling, inspect the coolant recovery system. Does the coolant recovery system discharge coolant while the engine is idling?Go to Step 15Go to Step 11
11Visually inspect the hoses, pipes, and hose clamps at the following locations: The auxiliary heater core The coolant reservoir The heater core The radiator Are any of the hoses, clamps, or pipes leaking?Go to Step 24Go to Step 12
12Visually inspect the following components: The block heater The coolant pressure cap The coolant reservoir The core plugs The cylinder head gaskets The engine block The intake manifold The radiator The thermostat The water pump Are any of the listed components leaking?Go to Step 24Go to Step 13
13Pressure test the cooling system. Refer to Cooling System Leak Testing . Visually inspect the components listed in steps 11 and 12 again. Are any leaks present?Go to Step 24Go to Step 14
14Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure?Go to Step 16Go to Step 25
15Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure?Go to Step 35Go to Step 25
16Inspect for the following conditions: A coolant smell inside of the vehicle Coolant in the HVAC module assembly drain tube Coolant on the vehicle floor covering under the HVAC module assembly Is coolant present?Go to Step 26Go to Step 17
17If equipped with auxiliary heating, inspect for the following conditions: A coolant smell inside of the vehicle Coolant in the auxiliary HVAC module assembly drain tube Coolant on the floor covering near the auxiliary HVAC module assembly Is coolant present?Go to Step 27Go to Step 18
18Add 30 ml (1 oz) of Extended Life Coolant Leak Detection Dye GM P/N 89022219 (Canadian P/N 89022220) to the cooling system for each 15 liters (4 gallons) of coolant. Refer to Approximate Fluid Capacities . Start the vehicle and allow the engine to reach normal operating temperature. Shut the engine off. Use J 42220 universal 12V leak detection lamp to visually inspect the components listed in steps 11 and 12. Are any leaks present?Go to Step 24Go to Step 19
19Use J 42220 universal 12V leak detection lamp to inspect for the following conditions: Coolant dye in the HVAC module drain tube Coolant dye on the vehicle floor covering near the HVAC module Is coolant dye present?Go to Step 26Go to Step 20
20Use J 42220 universal 12V leak detection lamp to inspect for the following conditions: Coolant dye in the auxiliary HVAC module drain tube Coolant dye on the vehicle floor covering near the auxiliary HVAC module Is coolant dye present?Go to Step 27Go to Step 21
21Inspect the underside of the oil fill cap for a gray/white milky substance. Is there a milky substance under the oil fill cap?Go to Step 22Go to Step 23
22Inspect the engine oil fluid level indicator for a gray/white milky substance. Is there a milky substance on the engine oil fluid level indicator?Go to Step 33Go to Step 23
23Inspect the automatic transmission oil fluid level indicator, if equipped, for a gray/white milky substance. Is there a milky substance on the automatic transmission fluid level indicator?Go to Step 28Go to Step 36
24Repair or replace the leaking component. Refer to the appropriate repair. Is the repair complete?Go to Step 36
25Replace the coolant pressure cap. Is the repair complete?Go to Step 36
26Replace the heater core. Refer to Heater Core Replacement . Is the repair complete?Go to Step 36
27Replace the auxiliary heater core. Refer to Auxiliary Heater Core Replacement . Is the repair complete?Go to Step 36
28Remove the transmission oil cooler lines from the radiator. Pressure test the cooling system. Refer to Cooling System Leak Testing . Inspect the transmission oil cooler for coolant. Is coolant present in the transmission oil cooler?Go to Step 29Go to Step 30
29Replace the radiator. Refer to Radiator Replacement (Acadia, OUTLOOK, Traverse) . Service the automatic transmission. Refer to Engine Coolant/Water in Transmission . Is the repair complete?Go to Step 36
30Install the cooler lines to the radiator. Is the action complete?Go to Step 36
31Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate . Is the repair complete?Go to Step 36
32Repair the engine overheating condition. Refer to Engine Overheating . Is the repair complete?Go to Step 36
33Repair the engine internal coolant leak. Refer to Coolant in Combustion Chamber , or Coolant in Engine Oil . Is the repair complete?Go to Step 36
34Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed . Is the repair complete?Go to Step 36
35Repair the combustion pressure in the cooling system problem. Refer to Coolant in Combustion Chamber . Is the repair complete?Go to Step 36
36Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Loss of Coolant

Thermostat Diagnosis

Tools Required

  1. J 24731 188 Tempilstick
  2. J 24731 206 Tempilstick

The coolant thermostat can be tested using a temperature (tempil) stick. The temperature stick is a pencil-like device which has a wax material containing certain chemicals that melt at a given temperature. Temperature sticks can be used to determine a thermostat's operating range by rubbing 87°C (188°F) and 97°C (206°F) sticks on the outlet coolant pipe.

  1. Use a tempilstick in order to find the opening and the closing temperatures of the thermostat. J 24731 188 Tempilstick melts at 87°C (188°F). The thermostat should begin to open at 90°C (194°F). J 24731 206 tempilstick melts at 97°C (206°F). The thermostat should be fully open at 107°C (225°F).
  2. Replace the thermostat if it does not operate properly between this temperature range.
  1. Perform the «Diagnostic System Check - Vehicle»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/buick/enclave/i-2007-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

Electrical Information Reference

  1. «Circuit Testing»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Note. The power supply cord will read open due to an internal thermal switch if the ambient temperature is above -18°C (0°F).

  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»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system)
  2. «Coolant Heater Cord Replacement»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Fails To Reach Normal Operating Temperature

StepActionYesNo
1Ensure that the cooling system is full. Allow the engine to cool. Start the engine. Turn the air conditioning system off. Inspect the engine cooling fan(s). Is the electric cooling fan on?Go to Step 2Go to Step 3
2Diagnose and repair the cooling fan system. Refer to Cooling Fan Always On . Verify the customer complaint. Does the engine still fail to reach normal operating temperature?Go to Step 3System OK
3Install the Scan Tool to the DLC. Compare the Scan Tool coolant temperature reading to the I/P cluster coolant temperature. Is the I/P cluster coolant temperature close to the reading on the Scan Tool?Go to Step 5Go to Step 4
4Diagnose and repair the coolant temperature gauge system. Verify the customer complaint. Does the engine still fail to reach normal operating temperature?Go to Step 5System OK
5Inspect the thermostat for proper operation. Refer to Thermostat Diagnosis . Is the thermostat operating properly?Go to Step 1Go to Step 6
6Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Verify the customer complaint. Does the engine still fail to reach normal operating temperature?Go to Step 1System OK

Engine Fails To Reach Normal Operating Temperature

Radiator Pressure Cap Testing

Special Tools

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

Special Tools

J-24460-01 Cooling System Pressure Tester

  1. Remove the pressure cap.
  2. Test the operation of the pressure cap. Refer to «Pressure Cap Testing»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__radiator-pressure-cap-testing) .
  3. Use the J-24460-01 tester in order to apply pressure to the cooling system. Do not exceed the pressure cap rating.
  4. The cooling system should hold the rated pressure for at least 2 minutes. Observe the gauge for any pressure loss.
  5. Repair any leaks as required.

Draining Procedure

Special Tools

J 26568 Coolant and Battery Tester

WARNINGTo avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
  1. Place a drain pan under the radiator hose.
  2. Remove the radiator outlet hose from the engine. Refer to «Radiator Outlet Hose Replacement»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Move down the end of the radiator hose to drain the radiator.
  4. Drain the cooling system.
  5. Remove the coolant pressure cap.
  6. If a complete engine block drain is required, remove the engine drain plugs.
  7. Inspect the coolant.
  8. 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»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Filling Procedure

  1. Install the radiator outlet hose to the engine. Refer to «Radiator Outlet Hose Replacement»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. If the engine block drain plug was removed, perform the following: Apply pipe sealer to the drain plugs. Install the drain plugs. Tighten Tighten the drain plug to 22 N.m (16 lb ft).
  3. Lower the vehicle.
  4. Slowly fill the cooling system with a 50/50 coolant mixture. Refer to «Approximate Fluid Capacities»(/buick/enclave/i-2007-2013/remont/lubrication-system/#maintenance-and-lubrication__approximate-fluid-capacities) .
  5. Install the coolant pressure cap.
  6. Start the engine.
  7. Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
  8. Allow the engine to idle for 3 minutes.
  9. Shut the engine OFF.
  10. Allow the engine to cool.
  11. Top off the coolant as necessary.
  12. Inspect the concentration of the engine coolant, using the J 26568 coolant and battery tester.
  13. Rinse away any excess coolant from the engine and the engine compartment.

Special Tools

  1. GE-47716 Vac-N-Fill Coolant Refill Tool
  2. J 26568 Coolant and Battery Tester
WARNINGTo avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
  1. Remove the radiator cap.
  2. Attach the venturi assembly to the vacuum tank.
  3. Attach a shop air hose to the venturi assembly. Ensure the valve on the venturi assembly is closed.
  4. Attach the vacuum hose to the vacuum tank .
  5. Attach the extraction hose to the vacuum hose.
  6. Insert the extraction hose into the radiator cap opening and into the radiator until the extraction hose contacts the bottom of the radiator end tank.
  7. Open the valve on the venturi assembly to start a vacuum draw.
  8. Use the extraction hose to draw out coolant until the radiator is empty.
  9. 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.
  10. If a complete engine block drain is required, remove the engine block drain plug.
  11. Inspect the coolant.
  12. 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»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Vac-N-Fill Procedure

Note. To prevent boiling of the coolant/water mixture in the vehicles cooling system, do not apply vacuum to a cooling system above 49°C (120°F). The tool will not operate properly when the coolant is boiling.

  1. Attach the Vac-N-Fill cap to the vehicles coolant fill port.
  2. Install the extension hose.
  3. Attach the vacuum gauge assembly to the Vac-N-Fill cap.
  4. Attach the fill hose to the barb fitting on the vacuum gauge assembly. Ensure that the valve is closed.
  5. Pour the coolant mixture into the graduated reservoir.
  6. Place the fill hose in the graduated reservoir.
  7. Install the vacuum tank on the graduated reservoir with the fill hose routed through the cut-out area in the vacuum tank.
  8. Attach the venturi assembly to the vacuum tank.
  9. Attach a shop air hose to the venturi assembly. Ensure the valve on the venturi assembly is closed.
  10. Attach the vacuum hose to the vacuum gauge assembly and the vacuum tank.
  11. Clamp off the overflow hose.
  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. To aid in the fill process, position the graduated reservoir above the coolant fill port.
  15. 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.
  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»(/buick/enclave/i-2007-2013/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. Remove the extension hose.
  20. Remove the J 42401 radiator cap and surge tank test adapter.
  21. Detach the Vac-N-Fill cap from the vehicles coolant fill port.
  22. Add coolant to the system as necessary.
  23. Inspect the concentration of the coolant mixture using J 26568 coolant and battery tester.
  24. Detach the vacuum hose form 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. The vacuum tank has a drain valve on the bottom of the tank. Open the valve to drain coolant from the vacuum tank into a suitable container for disposal.

Flushing

IMPORTANTDo not use a chemical flush.

Store used coolant in the proper manner, such as in a used engine coolant holding tank. 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. Always remove the thermostat before flushing the cooling system.

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 (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the coolant recovery reservoir. Refer to «Coolant Recovery Reservoir Replacement»(/buick/enclave/i-2007-2013/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»(/buick/enclave/i-2007-2013/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 (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/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 (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/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 (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .

Radiator Cleaning

WARNINGNEVER spray water on a hot heat exchanger. The resulting steam could cause personal injury.
CAUTIONThe heat exchanger fins are necessary for good heat transfer. Do not brush the fins. This may cause damage to the fins, reducing heat transfer.
  1. Some conditions may require the use of warm water and a mild detergent.
  2. Clean the A/C condenser fins.
  3. Clean between the A/C condenser and radiator.
  4. Clean the radiator cooling fins.
  5. Straighten any damaged cooling fins.

Scheme 2

Scheme 2: Coolant Recovery Reservoir Replacement
Scheme 2: Coolant Recovery Reservoir Replacement
CalloutComponent Name
Preliminary Procedure Drain the coolant from the recovery reservoir. Remove the front compartment sight shield if necessary. Refer to Front Compartment Sight Shields Replacement (Traverse) , Front Compartment Sight Shields Replacement (Acadia) , Front Compartment Sight Shields Replacement (Enclave)
1Coolant Recovery Reservoir Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Tighten 5 N.m (44 lb in)
2Coolant Recovery Reservoir Procedure Remove overflow hose from reservoir
CAUTION
Refer to Fastener Caution .

Coolant Recovery Reservoir Replacement

Scheme 3

Scheme 3: Radiator Inlet Hose Replacement
Scheme 3: Radiator Inlet Hose Replacement
CalloutComponent Name
Preliminary Procedures Drain the coolant. Refer to Cooling System Draining and Filling (Static Fill) , Cooling System Draining and Filling (Vac N Fill) . Remove the front compartment sight shield. Refer to Front Compartment Sight Shields Replacement (Traverse) , Front Compartment Sight Shields Replacement (Acadia) , Front Compartment Sight Shields Replacement (Enclave) .
1Radiator Inlet Hose Clamp (Qty: 2) Procedure Using J 38185 hose clamp pliers reposition the radiator inlet hose clamps. Special Tools J 38185 Hose Clamp Pliers
2Radiator Inlet Hose

Radiator Inlet Hose Replacement

Scheme 4

Scheme 4: Radiator Outlet Hose Replacement
Scheme 4: Radiator Outlet Hose Replacement
CalloutComponent Name
Preliminary Procedures Drain the coolant. Refer to Cooling System Draining and Filling (Static Fill) , Cooling System Draining and Filling (Vac N Fill) . Remove the front compartment sight shield. Refer to Front Compartment Sight Shields Replacement (Traverse) , Front Compartment Sight Shields Replacement (Acadia) , Front Compartment Sight Shields Replacement (Enclave) .
1Radiator Outlet Hose Clamp (Qty: 2) Procedure Using J 38185 hose clamp pliers reposition the radiator outlet hose clamps. Special Tools J 38185 Hose Clamp Pliers
2Radiator Outlet Hose

Radiator Outlet Hose Replacement

Scheme 5

Scheme 5: Engine Oil Cooler Connector Replacement
Scheme 5: Engine Oil Cooler Connector Replacement
CalloutComponent Name
Preliminary Procedures Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) , Cooling System Draining and Filling (Vac N Fill) . Remove the engine oil cooler pipe from the oil cooler fittings on the radiator. Refer to Engine Oil Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection .
1Engine Oil Cooler Fitting CAUTION: Refer to Fastener Caution . Procedure Remove the plastic caps from the quick connect fittings by pulling the caps back along the pipe before installation. Do not remove the upper and lower engine oil cooler fittings from the radiator at the same time, otherwise the engine oil cooler may fall inside the radiator end tank. The correct thread engagement is critical. Cross-threaded fittings can achieve proper tightness and still leak. Tighten 24 N.m (18 lb ft)
CAUTION
Refer to Fastener Caution .

Engine Oil Cooler Connector Replacement

Engine Oil Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection

Special Tools

  1. DT-47731 1/2 in. Cooler Line Quick Release Tool
  2. J 28585 Universal Snap Ring Remover for the 5/8 in. Cooler Line

Removal Procedure

  1. Remove the plastic caps from the quick connect fittings by pulling the caps back along the pipe before installation.
  2. Install the DT-47731 1/2 in. cooler line quick release tool onto the transmission oil cooler (TOC) pipe, or use the J 28585 universal snap ring remover for the 5/8 in. cooler line.
  3. Slide the DT-47731 1/2 in. cooler line quick release tool toward the TOC pipe fitting, or use the J 28585 universal snap ring remover for the 5/8 in. cooler line.
  4. Connect the DT-47731 1/2 in. cooler line quick release tool onto the TOC pipe fitting.
  5. Rotate the DT-47731 1/2 in. cooler line quick release tool or use the J 28585 universal snap ring remover for the 5/8 in. cooler line until the retainer clip (1) rises above the fitting retainer seat.
  6. Pull back on the TOC pipe to disengage the pipe from the TOC pipe fitting.
  7. Remove the DT-47731 1/2 in. cooler line quick release tool or the J 28585 universal snap ring remover for the 5/8 in. cooler line from the TOC pipe.

Installation Procedure

  1. Install the TOC pipe into the TOC pipe fitting. A distinct snap should be heard or felt when assembling the TOC pipe to the fitting.
  2. To ensure the cooler line is properly installed, give the cooler pipe a gentle pull.

Scheme 6

Scheme 6: Cooling Fan and Shroud Replacement
Scheme 6: Cooling Fan and Shroud Replacement
CalloutComponent Name
Preliminary Procedure Remove front bumper impact bar. Refer to Front Bumper Impact Bar Replacement . Remove radiator inlet hose at radiator. Refer to Radiator Inlet Hose Replacement . Disconnect electrical connector at fan shroud harness. Remove front fascia upper support. Refer to Front Bumper Fascia Upper Support Replacement (Enclave) , Front Bumper Fascia Upper Support Replacement (Acadia and Traverse) . Remove hood latch. Refer to Hood Primary and Secondary Latch Replacement . Remove upper radiator mounting brackets and tip radiator forward for additional clearance.
1Fan Shroud Mounting Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Procedure Remove small pushpin retainers. Tighten 10 N.m (89 lb in)
2Fan Shroud Procedure Tilt fan shroud rearward and upward to remove. TIP: Reposition of radiator hoses my be necessary for removal.
CAUTION
Refer to Fastener Caution .

Cooling Fan and Shroud Replacement

Scheme 7

Scheme 7: Engine Coolant Thermostat Replacement
Scheme 7: Engine Coolant Thermostat Replacement
CalloutComponent Name
Preliminary Procedures Partially drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) , Cooling System Draining and Filling (Vac N Fill) . Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement . Remove the heater inlet and outlet hoses. Refer to Heater Inlet Hose Replacement , and Heater Outlet Hose Replacement .
1Thermostat Housing Bolt (Qty: 3) CAUTION: Refer to Fastener Caution . Procedure Remove the thermostat housing bolts. Tighten 10 N.m (89 lb in)
2Thermostat Housing Retainer Bolt Procedure Remove the thermostat housing retainer bolt. Tighten 50 N.m (37 lb ft)
3Thermostat Housing
4Thermostat Procedure Remove the thermostat and discard the thermostat gasket. Install a new thermostat gasket.
CAUTION
Refer to Fastener Caution .

Engine Coolant Thermostat Replacement

Scheme 8

Scheme 8: Water Outlet Replacement
Scheme 8: Water Outlet Replacement
CalloutComponent Name
Preliminary Procedures Remove the radiator inlet hose. Refer to Radiator Inlet Hose Replacement . Remove the right engine mount strut bracket.Refer to Engine Mount Strut Bracket Replacement - Right Side .
1Water Outlet Housing Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Procedure Remove the water outlet housing bolts. Tighten 10 N.m (89 lb in)
2Water Outlet Housing
3Seal Procedure Remove the water outlet housing seal. Discard the seal. Install a new water outlet housing seal.
CAUTION
Refer to Fastener Caution .

Water Outlet Replacement

Water Pump Replacement

Special Tools

EN 46104 Water Pump Pulley Holding Tool

  1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the drive belt. Refer to «Drive Belt Replacement»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle) .
  3. Remove the right engine strut mount. Refer to «Engine Mount Strut Replacement - Right Side»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle) .
  4. Remove the right engine mount strut bracket. Refer to «Engine Mount Strut Bracket Replacement - Right Side»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle) .
  5. Use the EN 46104 tool in order to retain the water pump pulley.
  6. Remove the water pump pulley bolts.
  7. Remove the water pump pulley.
  8. Remove the water pump bolts.
  9. Remove the water pump.
  10. Remove and DISCARD the water pump seal.
  11. Carefully clean the water pump sealing surfaces.
  1. Install a NEW water pump seal.
  2. Install the water pump.
  3. Hand tighten the water pump bolts.
  4. Tighten the water pump bolts in sequence to 12 N.m (106 lb in).
  5. Tighten the water pump bolts a second pass in sequence to 12 N.m (106 lb in).
  6. Install the water pump pulley and the water pump pulley bolts.
  7. Use the EN 46104 tool in order to retain the water pump pulley.
  8. Install the water pump pulley bolts and tighten to 10 N.m (89 lb in).
  9. Install the right engine strut mount. Refer to «Engine Mount Strut Replacement - Right Side»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle) .
  10. Install the right engine mount strut bracket. Refer to «Engine Mount Strut Bracket Replacement - Right Side»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle) .
  11. Install the drive belt. Refer to «Drive Belt Replacement»(/buick/enclave/i-2007-2013/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle) .
  12. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling System Draining and Filling (Vac N Fill)»(/buick/enclave/i-2007-2013/remont/cooling-system-mechanical/#engine-cooling-system) .

Scheme 9

Scheme 9: Radiator Replacement (Acadia, Traverse)
Scheme 9: Radiator Replacement (Acadia, Traverse)
CalloutComponent Name
Preliminary Procedure Drain the coolant. Refer to Cooling System Draining and Filling (Static Fill) , Cooling System Draining and Filling (Vac N Fill) Remove radiator inlet hose. Refer to Radiator Inlet Hose Replacement . Remove radiator outlet hose. Refer to Radiator Outlet Hose Replacement . Remove fan shroud top mounting bolts and pushpin from radiator and position fan shroud rearward. Refer to Cooling Fan and Shroud Replacement . Remove transmission inlet cooling line from radiator. Refer to Fluid Cooler Inlet Hose Replacement . Remove transmission outlet cooling line from radiator. Refer to Fluid Cooler Outlet Hose Replacement . Remove coolant reservoir hose from radiator filler neck. Remove the front bumper fascia upper support. Refer to Front Bumper Fascia Upper Support Replacement (Enclave) , Front Bumper Fascia Upper Support Replacement (Acadia and Traverse) Pinch fastening tabs together at top of condenser to remove from radiator and position forward. Remove side rubber air deflectors from radiator tanks.
1Radiator Mounting Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Tighten 10 N.m (89 lb in)
2Radiator Bottom of condenser mounts into holding fixtures at bottom of radiator. Radiator will slide out between the condenser and fan shroud.
CAUTION
Refer to Fastener Caution .

Radiator Replacement (Acadia, Traverse)

Scheme 10

Scheme 10: Coolant Heater Replacement
Scheme 10: Coolant Heater Replacement
CalloutComponent Name
Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
1Coolant Heater Procedure Disconnect the coolant heater cord from the coolant heater. Remove the coolant heater.

Coolant Heater Replacement

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
  2. Disconnect the coolant heater power supply cord from the coolant heater.
  3. Lower the vehicle.
  4. Disconnect the coolant heater cord clips (3) from the cylinder heads.
  5. Disconnect the coolant heater cord clip from the engine wiring harness.
  6. Remove the coolant heater cord (1) from the vehicle.
  1. Position the coolant heater cord (1) to the engine harness.
  2. Connect the coolant heater cord clip to the engine wiring harness.
  3. Connect the coolant heater cord clips (3) to the cylinder heads.
  4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/enclave/i-2007-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
  5. Connect the coolant heater cord to the coolant heater.
  6. Lower the vehicle.

Scheme 11

Scheme 11: Cooling Fan Description and Operation
Scheme 11: Cooling Fan Description and Operation

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel (S/P) 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 1 relay through the fan 1 relay control circuit. This energizes the fan 1 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 engine cooling fan. The ground path for the left cooling fan is through the S/P fan 2 relay and the right engine cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the ECM continues to supply battery positive voltage for the right cooling fan by grounding the coil of the fan 1 relay. The ECM also grounds the high speed fan 3 relay and the S/P fan 2 relay through the fan 3 relay control circuit. This energizes the S/P fan 2 relay coil, closes the relay contacts, and provides a direct ground path for the left engine cooling fan. At the same time the fan 3 relay coil is energized closing the relay contacts and providing 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.

Cooling System Description and Operation

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.

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

Coolant

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

Radiator

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

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

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.

Transmission Oil Cooler

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.

Special Tools

Illustration Tool Number/ Description GE-47716 Vac N Fill Coolant Refill Tool J-24460-01 Cooling System Pressure Tester J-26568 Coolant and Battery Fluid Tester J-38185 Hose Clamp Pliers J-42401 Radiator Cap and Surge Tank Test Adapter

Scheme 12

Scheme 12: Special Tools
Scheme 12: Special Tools

Scheme 13

Scheme 13
Scheme 13

Scheme 14

Scheme 14
Scheme 14

Scheme 15

Scheme 15
Scheme 15

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• COMPONENT CONNECTOR END VIEWS - INDEX
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Relay Replacement (Within an Electrical Center)
• Relay Replacement (Attached to Wire Harness)
• Engine Controls Schematics
• Instrument Cluster Description and Operation
• Engine Control Module Scan Tool Information (LLT)
• Water Pump Cleaning and Inspection
• Coolant in Engine Oil
• Diagnostic Trouble Code (DTC) List - Vehicle
• Diagnostic Starting Point - Vehicle
• Approximate Fluid Capacities
• Heater Core Replacement
• Engine Coolant/Water in Transmission
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Coolant in Combustion Chamber
• Lower Engine Noise, Regardless of Engine Speed
• Fastener Caution
• Front Compartment Sight Shields Replacement (Traverse)
• Front Bumper Impact Bar Replacement
• Air Cleaner Outlet Duct Replacement
• Engine Mount Strut Bracket Replacement - Right Side
• Fluid Cooler Inlet Hose Replacement
• Fluid Cooler Outlet Hose Replacement
• Lifting and Jacking the Vehicle
• DTC P0480, P0481, P0691, P0692, P0693, or P0694
• Cooling System Description and Operation
• Thermostat Diagnosis
• Engine Overheating
• Loss of Coolant
• Engine Fails To Reach Normal Operating Temperature
• Flushing
• Water Pump Replacement
• Pressure Cap Testing
• Engine Oil Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection