Reference Information
Schematic Reference
Engine Heating/Cooling Schematics
Connector End View Reference
- «COMPONENT CONNECTOR END VIEWS - INDEX»(ref-610289-S27831341712014042200000)
- «Electrical Center Identification Views»(ref-610111-S08570912712014042100000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-610066-S15766520632014042100000)
- «Connector Repairs»(ref-610066-S09830970062014042100000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-610066-S03531120952014042100000)
- «Wiring Repairs»(ref-610066-S23061455012014042100000)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON.
- Verify an audible click is heard or felt from cooling fan relays 1, 2 and 3 when commanding the cooling fans ON and OFF with a scan tool. If a click is not heard or felt at one or more of the relays Refer to «Circuit/System Testing»(ref-610069-S32873261012014042100000) If a click is heard or felt at each of the relays
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
- Verify the DTC does not set. If the DTC sets Refer to «Circuit/System Testing»(ref-610069-S32873261012014042100000) If the DTC does not set
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- «Relay Replacement (Within an Electrical Center)»(ref-610058-S14101709942014042100000) , «Relay Replacement (Attached to Wire Harness)»(ref-610058-S15205971202014042100000)
- «Control Module References»(ref-610060-S10098619762014042100000) for ECM replacement, setup and programming
Schematic Reference
Engine Controls Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
Description and Operation
- «Cooling Fan Description and Operation»(ref-610069-S29149479542014042100000)
- «Instrument Cluster Description and Operation»(ref-610056-S17901943942014042100000)
- «Indicator/Warning Message Description and Operation»(ref-610056-S31399676422014042100000)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
K20 Engine Control Module: Scan Tool Information (LLT) for scan tool information
- Ignition ON.
- Verify DTC P0480, P0481, P0691, P0692, P0693 or P0694 is not set. If a DTC is set Refer to «DTC P0480, P0481, P0691, P0692, P0693 or P0694»(ref-610069-S36922063372014042100000) . If no DTCs is set
- Verify the cooling fan operates at each available speed as commanded with a scan tool. NOTE: A short delay occurs before the ECM changes the cooling fan speed. Cooling fan does not operate Refer to «Cooling Fan Inoperative»(ref-610069-S29862748052014042100000) . Cooling fan operates
- Verify that the engine does not overheat. Engine overheats Refer to «Engine Overheating»(ref-610069-S12444056302014042100000) . Engine does not overheat
- Operate the vehicle within the Conditions for Running the DTC. If the DTC sets Refer to «Symptoms - Engine Cooling»(ref-610069-S11890494322014042100000) . If the DTC does not set
- All OK
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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
- Water intrusion in connectors, terminals or components
- Poor connector mating
- Terminal contact
- High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
- Harness' that are routed too tight or chaffed circuits
- High or low ambient temperatures
- High or low engine coolant temperatures
- High underhood temperatures
- Heat build up in components or circuits due to circuit resistance, poor terminal contact or high electrical load
- High or low system voltage
- High vehicle load conditions
- Rough road surface
- Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
- Incorrect installation of non-factory, aftermarket or after factory add on accessories
If an intermittent fault is detected, refer to Testing for Intermittent Conditions and Poor Connections for specific strategies in diagnosing intermittent conditions.
Schematic Reference
Engine Heating/Cooling Schematics
Connector End View Reference
- «COMPONENT CONNECTOR END VIEWS - INDEX»(ref-610289-S27831341712014042200000)
- «Electrical Center Identification Views»(ref-610111-S08570912712014042100000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-610066-S15766520632014042100000)
- «Connector Repairs»(ref-610066-S09830970062014042100000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-610066-S03531120952014042100000)
- «Wiring Repairs»(ref-610066-S23061455012014042100000)
Scan Tool Reference
Control Module References for scan tool information
- Ignition ON.
- Verify that DTC P0480, P0481, P0691, P0692, P0693 or P0694 is not set. If a DTC is set Refer to «DTC P0480, P0481, P0691, P0692, P0693 or P0694»(ref-610069-S36922063372014042100000) . If no DTC is set
- Verify the scan tool parameters listed below display OFF: Cooling Fan Relay 1 Command Cooling Fan Relays 2 and 3 Command If a scan tool parameter displays ON Refer to «Diagnostic Aids»(ref-610069-S39522972672014042100000) and «Symptoms - Engine Cooling»(ref-610069-S11890494322014042100000) for further diagnosis. If both scan tool parameters display OFF
- Verify that the fans are not activated. If a fan is operating Refer to «Circuit/System Testing»(ref-610069-S38384360062014042100000) . If both fans are OFF
- All OK
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Relay Replacement (Within an Electrical Center) , Relay Replacement (Attached to Wire Harness)
Schematic Reference
Engine Heating/Cooling Schematics
Connector End View Reference
- «COMPONENT CONNECTOR END VIEWS - INDEX»(ref-610289-S27831341712014042200000)
- «Electrical Center Identification Views»(ref-610111-S08570912712014042100000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-610066-S15766520632014042100000)
- «Connector Repairs»(ref-610066-S09830970062014042100000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-610066-S03531120952014042100000)
- «Wiring Repairs»(ref-610066-S23061455012014042100000)
Scan Tool Reference
Control Module References for scan tool information
- Ignition ON.
- Verify that DTC P0480, P0481, P0691, P0692, P0693 or P0694 is not set. If a DTC is set Refer to «DTC P0480, P0481, P0691, P0692, P0693 or P0694»(ref-610069-S36922063372014042100000) . If no DTCs is set
- Verify that both cooling fans turn ON and OFF and operate at low and high speed, when commanding the appropriate cooling fan relays ON and OFF with a scan tool. If a cooling fan does not operate Refer to «Circuit/System Testing»(ref-610069-S18038721622014042100000) If both cooling fans operate
- All OK.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- «Relay Replacement (Within an Electrical Center)»(ref-610058-S14101709942014042100000) , «Relay Replacement (Attached to Wire Harness)»(ref-610058-S15205971202014042100000)
- «Cooling Fan and Shroud Replacement»(ref-610069-S27549627662014042100000)
Engine Overheating
| Step | Action | Yes | No |
|---|---|---|---|
| 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. | |||
| 1 | Inspect 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 | |
| 2 | Start 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 3 | Go to Diagnostic System Check - Vehicle |
| 3 | Verify that the cooling fans are operating properly. Repair the cooling fan system, as necessary. Does the engine still overheat? | Go to Step 4 | System OK |
| 4 | Perform 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 5 | System OK |
| 5 | Inspect the thermostat for proper operation. Refer to Thermostat Diagnosis . Is the thermostat operating properly? | Go to Step 7 | Go to Step 6 |
| 6 | Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Does the engine still overheat? | Go to Step 7 | System OK |
| 7 | Inspect for the proper coolant concentration (mixture). Correct the coolant concentration as necessary. IMPORTANT: Excessive coolant freeze point protection MAY cause the coolant to boil at low temperatures. 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 8 | Go to Step 9 |
| 8 | The 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 1 | System OK |
| 9 | The 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 10 | System OK |
| 10 | IMPORTANT: 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 1 | System 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
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The cooling system is losing coolant either internally or externally. | |||
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - Engine Cooling |
| 2 | Repair any present DTCs. Refer to Diagnostic Starting Point - Vehicle . Is the action complete? | Go to Step 3 | |
| 3 | Inspect the coolant level. Is the coolant at the proper level? | Go to Step 5 | Go to Step 4 |
| 4 | Fill 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 | |
| 5 | If 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 6 | Go to Step 31 |
| 6 | Engine overheating can cause a loss of coolant. Is the engine overheating? | Go to Step 32 | Go to Step 7 |
| 7 | Extended engine operation with a low coolant level can cause engine internal component failure. Is the engine knocking? | Go to Step 34 | Go to Step 8 |
| 8 | Idle 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 9 | Go to Step 10 |
| 9 | Coolant 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 33 | Go to Step 10 |
| 10 | With the engine idling, inspect the coolant recovery system. Does the coolant recovery system discharge coolant while the engine is idling? | Go to Step 15 | Go to Step 11 |
| 11 | Visually 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 24 | Go to Step 12 |
| 12 | Visually 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 24 | Go to Step 13 |
| 13 | Pressure 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 24 | Go to Step 14 |
| 14 | Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure? | Go to Step 16 | Go to Step 25 |
| 15 | Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure? | Go to Step 35 | Go to Step 25 |
| 16 | Inspect 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 26 | Go to Step 17 |
| 17 | If 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 27 | Go to Step 18 |
| 18 | Add 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 24 | Go to Step 19 |
| 19 | Use 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 26 | Go to Step 20 |
| 20 | Use 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 27 | Go to Step 21 |
| 21 | Inspect 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 22 | Go to Step 23 |
| 22 | Inspect 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 33 | Go to Step 23 |
| 23 | Inspect 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 28 | Go to Step 36 |
| 24 | Repair or replace the leaking component. Refer to the appropriate repair. Is the repair complete? | Go to Step 36 | |
| 25 | Replace the coolant pressure cap. Is the repair complete? | Go to Step 36 | |
| 26 | Replace the heater core. Refer to Heater Core Replacement . Is the repair complete? | Go to Step 36 | |
| 27 | Replace the auxiliary heater core. Refer to Auxiliary Heater Core Replacement . Is the repair complete? | Go to Step 36 | |
| 28 | Remove 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 29 | Go to Step 30 |
| 29 | Replace the radiator. Refer to Radiator Replacement . Service the automatic transmission. Refer to Engine Coolant/Water in Transmission . Is the repair complete? | Go to Step 36 | |
| 30 | Install the cooler lines to the radiator. Is the action complete? | Go to Step 36 | |
| 31 | Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate . Is the repair complete? | Go to Step 36 | |
| 32 | Repair the engine overheating condition. Refer to Engine Overheating . Is the repair complete? | Go to Step 36 | |
| 33 | Repair the engine internal coolant leak. Refer to Coolant in Combustion Chamber or Coolant in Engine Oil . Is the repair complete? | Go to Step 36 | |
| 34 | Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed . Is the repair complete? | Go to Step 36 | |
| 35 | Repair the combustion pressure in the cooling system problem. Refer to Coolant in Combustion Chamber . Is the repair complete? | Go to Step 36 | |
| 36 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
Loss of Coolant
Electrical Information Reference
- «Circuit Testing»(ref-610066-S15766520632014042100000)
- «Connector Repairs»(ref-610066-S09830970062014042100000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-610066-S03531120952014042100000)
- «Wiring Repairs»(ref-610066-S23061455012014042100000)
Perform the Diagnostic Repair Verification after completing the diagnostic repair.
- «Coolant Heater Replacement»(ref-610069-S19424146252014042100000)
- «Coolant Heater Cord Replacement»(ref-610069-S19004070552014042100000)
Engine Fails To Reach Normal Operating Temperature
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Ensure 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 2 | Go to Step 3 |
| 2 | Diagnose 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 3 | System OK |
| 3 | Install 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 5 | Go to Step 4 |
| 4 | Diagnose and repair the coolant temperature gauge system. Verify the customer complaint. Does the engine still fail to reach normal operating temperature? | Go to Step 5 | System OK |
| 5 | Inspect the thermostat for proper operation. Refer to Thermostat Diagnosis . Is the thermostat operating properly? | Go to Step 1 | Go to Step 6 |
| 6 | Replace 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 1 | System OK |
Engine Fails To Reach Normal Operating Temperature
Filling Procedure
- Install the radiator outlet hose to the engine. Refer to «Radiator Outlet Hose Replacement»(ref-610069-S17064136212014042100000) . CAUTION: The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.
- If the engine block drain plug was removed, perform the following: CAUTION: Refer to «Fastener Caution»(ref-610030-S34989781762014042100000) . Apply pipe sealer to the drain plugs. Install the drain plugs. Tighten Tighten the drain plug to 22 N.m (16 lb ft).
- Lower the vehicle.
- Slowly fill the cooling system with a 50/50 coolant mixture. Refer to «Approximate Fluid Capacities»(ref-610035-S10317435722014042100000) . NOTE: Use a 50/50 mixture of DEX-COOL antifreeze and clean, drinkable water.
- Install the coolant pressure cap.
- Start the engine.
- Run the engine at 2, 000-2, 500 RPM until the engine reaches normal operating temperature.
- Allow the engine to idle for 3 minutes.
- Shut the engine OFF.
- Allow the engine to cool.
- Top off the coolant as necessary.
- Inspect the concentration of the engine coolant, using the J 26568 coolant and battery tester.
- Rinse away any excess coolant from the engine and the engine compartment.
Radiator Cleaning
| WARNING | NEVER spray water on a hot heat exchanger. The resulting steam could cause personal injury. |
| CAUTION | The heat exchanger fins are necessary for good heat transfer. Do not brush the fins. This may cause damage to the fins, reducing heat transfer. |
- Some conditions may require the use of warm water and a mild detergent. NOTE: Remove bugs, leaves, dirt and other debris by blowing compressed air through the engine side of the radiator.
- Clean the A/C condenser fins.
- Clean between the A/C condenser and radiator.
- Clean the radiator cooling fins.
- Straighten any damaged cooling fins.
Scheme 38
| Callout | Component Name |
|---|---|
| Preliminary Procedures Drain the coolant from the recovery reservoir. Remove the front compartment sight shield if necessary. Refer to Front Compartment Front Sight Shield Replacement (Enclave) , Front Compartment Front Sight Shield Replacement (Traverse) , Front Compartment Front Sight Shield Replacement (Acadia) . | |
| 1 | Coolant Recovery Reservoir Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Tighten 5 (44 lb in) |
| 2 | Coolant Recovery Reservoir Procedure Remove the overflow hose from the reservoir. |
| CAUTION |
|---|
| Refer to Fastener Caution . |
Coolant Recovery Reservoir Replacement
Scheme 39
| Callout | Component 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 Front Sight Shield Replacement (Enclave) , Front Compartment Front Sight Shield Replacement (Traverse) , Front Compartment Front Sight Shield Replacement (Acadia) . | |
| 1 | Radiator 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 For equivalent regional tools, refer to Special Tools . |
| 2 | Radiator Inlet Hose |
Radiator Inlet Hose Replacement
Scheme 40
| Callout | Component 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 Front Sight Shield Replacement (Enclave) , Front Compartment Front Sight Shield Replacement (Traverse) , Front Compartment Front Sight Shield Replacement (Acadia) . | |
| 1 | Radiator 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 For equivalent regional tools, refer to Special Tools . |
| 2 | Radiator Outlet Hose |
Radiator Outlet Hose Replacement
Scheme 41
| Callout | Component 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 . | |
| 1 | Engine 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
- DT-47731 1/2 in. Cooler Line Quick Release Tool
- J 28585 Universal Snap Ring Remover for the 5/8 in. Cooler Line
Scheme 42
Scheme 43
Scheme 44
Scheme 45
Scheme 46
- Remove the plastic caps from the quick connect fittings by pulling the caps back along the pipe before installation.
- 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.
- 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.
- Connect the DT-47731 1/2 in. cooler line quick release tool onto the TOC pipe fitting. NOTE: Rotate the DT-47731 1/2 in. cooler line quick release tool to engage the TOC pipe fitting's retainer slots. The DT-47731 1/2 in. cooler line quick release tool should be nearly flush with the fitting.
- 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.
- Pull back on the TOC pipe to disengage the pipe from the TOC pipe fitting.
- 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.
Scheme 47
- Install the TOC pipe into the TOC pipe fitting. NOTE: Discard the TOC retaining clip and install a new retaining clip. A distinct snap should be heard or felt when assembling the TOC pipe to the fitting.
- To ensure the cooler line is properly installed, give the cooler pipe a gentle pull.
Scheme 48
| Callout | Component Name |
|---|---|
| Preliminary Procedure Remove front bumper impact bar. Refer to Front Bumper Impact Bar Replacement (Acadia) . 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 (Acadia, Enclave, Traverse) . Remove hood latch. Refer to Hood Primary and Secondary Latch Replacement . Remove upper radiator mounting brackets and tip radiator forward for additional clearance. | |
| 1 | Fan Shroud Mounting Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Procedure Remove small pushpin retainers. Tighten 10 N.m (89 lb in) |
| 2 | Fan 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 49
| Callout | Component 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 fuel pipe shield. Refer to Fuel Pipe Shield Replacement . Disconnect the radiator outlet hose from the thermostat housing. Refer to Radiator Outlet Hose Replacement . Remove the heater inlet and outlet hoses. Refer to Heater Inlet Hose Replacement and Heater Outlet Hose Replacement . | |
| 1 | Thermostat Housing Bolt (Qty: 3) CAUTION: Refer to Fastener Caution . Procedure Remove the thermostat housing bolts. Tighten 10 N.m (89 lb in) |
| 2 | Thermostat Housing Retainer Bolt Procedure Remove the thermostat housing retainer bolt. Tighten 50 N.m (37 lb ft) |
| 3 | Thermostat Housing |
| 4 | Thermostat Procedure Remove the thermostat and discard the thermostat gasket. Install a new thermostat gasket. |
| CAUTION |
|---|
| Refer to Fastener Caution . |
Engine Coolant Thermostat Replacement
Scheme 50
| Callout | Component 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 . | |
| 1 | Water Outlet Housing Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Procedure Remove the water outlet housing bolts. Tighten 10 N.m (89 lb in) |
| 2 | Water Outlet Housing |
| 3 | Seal 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
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
- The pressure valve is held against the seat by a spring that protects the radiator by relieving pressure that exceeds 15 psi.
- 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.