Reference Information
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
- «Cooling System Component Views»(ref-267956-S22056780362007101700000)
- «Cooling System Connector End Views»(ref-267956-S33699982772007101700000)
- «Engine Control Module Connector End Views»(ref-267935-S37861812022007101700000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-267924-S30300380662007101700000)
- «Connector Repairs»(ref-267924-S40546396332007101700000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-267924-S30568029692007101700000)
- «Wiring Repairs»(ref-267924-S21063363232007101700000)
- «Electrical Center Identification Views»(ref-267924-S15110937322007101700000)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
- «Scan Tool Data List»(ref-267956-S01550247952007101700000)
- «Scan Tool Data Definitions»(ref-267956-S32948624272007101700000)
- «Scan Tool Output Controls»(ref-267956-S05929489002007101700000)
Circuit/System Verification
Ignition ON, command each relay ON and OFF with a scan tool. Feel or listen to verify that each relay turns ON and OFF with each command.
Repair Procedures
Cooling Fan and Shroud Replacement
Repair Verification
Ignition ON, command the relay ON and OFF with a scan tool. Feel or listen to verify that the relay turns ON and OFF with each command.
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, command the cooling fan speed from 10-90 percent with a scan tool. The fan speed should transition with the commanded states.
- «Cooling Fan and Shroud Replacement»(ref-267956-S00730720482007101700000)
- «Control Module References»(ref-267925-S30181830442007101700000) for replacement, setup, and programming
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, command the cooling fan speed from 10-90 percent with a scan tool. The fan speed should transition with the commanded states.
Symptoms - Engine Cooling
| IMPORTANT | Review the system operation in order to familiarize yourself with the system functions. Refer to Cooling System Description and Operation . |
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
Cooling System Connector End Views
Description and Operation
Cooling System Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-267924-S30300380662007101700000)
- «Connector Repairs»(ref-267924-S40546396332007101700000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-267924-S30568029692007101700000)
- «Wiring Repairs»(ref-267924-S21063363232007101700000)
Scan Tool Reference
- «Scan Tool Data List»(ref-267956-S01550247952007101700000)
- «Scan Tool Output Controls»(ref-267956-S05929489002007101700000)
- Turn ON the ignition with the engine OFF.
- Command the instrument cluster indicators ON and OFF with a scan tool.
- The low coolant indicator lamp should turn ON and OFF on command.
- The low coolant indicator should be OFF with the engine coolant at the proper level.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- «Surge Tank Replacement»(ref-267956-S01562057212007101700000)
- «Control Module References»(ref-267925-S30181830442007101700000)
- «Instrument Cluster Replacement»(ref-267931-S18907368162007101700000)
Verify that the low coolant indicator is OFF with the engine coolant at the proper level.
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
- «Cooling System Component Views»(ref-267956-S22056780362007101700000)
- «Cooling System Connector End Views»(ref-267956-S33699982772007101700000)
- «Engine Control Module Connector End Views»(ref-267935-S37861812022007101700000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-267924-S30300380662007101700000)
- «Connector Repairs»(ref-267924-S40546396332007101700000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-267924-S30568029692007101700000)
- «Wiring Repairs»(ref-267924-S21063363232007101700000)
- «Electrical Center Identification Views»(ref-267924-S15110937322007101700000)
- If DTCs P0480 or P0481 are set, then perform those diagnostics first.
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, observe that the fan is not activated.
Cooling Fan and Shroud Replacement
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, observe that the fan is not activated.
Schematic Reference
- «Engine Cooling Schematics»(ref-267956-S40617411182007101700000)
- «Cooling System Component Views»(ref-267956-S22056780362007101700000)
Connector End View Reference
- «Cooling System Connector End Views»(ref-267956-S33699982772007101700000)
- «Engine Control Module Connector End Views»(ref-267939-S35325432092007101700000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-267924-S30300380662007101700000)
- «Connector Repairs»(ref-267924-S40546396332007101700000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-267924-S30568029692007101700000)
- «Wiring Repairs»(ref-267924-S21063363232007101700000)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
- «Scan Tool Data List»(ref-267956-S01550247952007101700000)
- «Scan Tool Data Definitions»(ref-267956-S32948624272007101700000)
- «Scan Tool Output Controls»(ref-267956-S05929489002007101700000)
- If DTCs P0480, P0691, or P0692 are set, perform that diagnostic first.
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, observe that the fan is not activated. If the fan is activated, replace the cooling fan assembly.
Perform the Cooling Fan and Shroud Replacement after completing the diagnostic procedure.
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, observe that the fan is not activated.
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
- «Cooling System Component Views»(ref-267956-S22056780362007101700000)
- «Cooling System Connector End Views»(ref-267956-S33699982772007101700000)
- «Engine Control Module Connector End Views»(ref-267935-S37861812022007101700000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-267924-S30300380662007101700000)
- «Connector Repairs»(ref-267924-S40546396332007101700000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-267924-S30568029692007101700000)
- «Wiring Repairs»(ref-267924-S21063363232007101700000)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
- «Scan Tool Data List»(ref-267956-S01550247952007101700000)
- «Scan Tool Data Definitions»(ref-267956-S32948624272007101700000)
- «Scan Tool Output Controls»(ref-267956-S05929489002007101700000)
- If DTCs P0480 or P0481 are set, perform those diagnostics first.
- Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that the fan turns ON and OFF with each command.
Cooling Fan and Shroud Replacement
Ignition ON, command the relay ON and OFF with a scan tool. Observe to verify that the fan turns ON and OFF with each command.
Schematic Reference
- «Engine Cooling Schematics»(ref-267956-S40617411182007101700000)
- «Cooling System Component Views»(ref-267956-S22056780362007101700000)
Connector End View Reference
- «Cooling System Connector End Views»(ref-267956-S33699982772007101700000)
- «Engine Control Module Connector End Views»(ref-267939-S35325432092007101700000)
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
- «Circuit Testing»(ref-267924-S30300380662007101700000)
- «Connector Repairs»(ref-267924-S40546396332007101700000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-267924-S30568029692007101700000)
- «Wiring Repairs»(ref-267924-S21063363232007101700000)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
- «Scan Tool Data List»(ref-267956-S01550247952007101700000)
- «Scan Tool Data Definitions»(ref-267956-S32948624272007101700000)
- «Scan Tool Output Controls»(ref-267956-S05929489002007101700000)
- If DTCs P0480, P0691, or P0692 are set, perform that diagnostic first.
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, command the cooling fan speed from 10-90 percent with a scan tool. The fan speed should transition with the commanded states.
- «Cooling Fan and Shroud Replacement»(ref-267956-S00730720482007101700000)
- «Control Module References»(ref-267925-S30181830442007101700000) for replacement, setup, and programming
- Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
- Ignition ON, command the cooling fan speed from 10-90 percent with a scan tool. The fan speed should transition with the commanded states.
Engine Overheating
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The engine temperature lamp comes on and stays on, or temperature gage shows hot, or coolant overflows from the surge tank onto the ground while the engine is running. | |||
| 1 | Check for a loss of coolant. Refer to Engine Overheating . Is there a loss of coolant? | Go to Step 2 | Go to Step 3 |
| 2 | Fill the system to the specified level. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Does the engine still overheat? | Go to Step 3 | System OK |
| 3 | Check for kinked or pinched surge tank hoses, especially at the radiator. Are any surge tank hoses kinked or pinched? | Go to Step 4 | Go to Step 5 |
| 4 | Relieve any kinks by rerouting the hoses. Replace the hoses, if necessary. Does the engine still overheat? | Go to Step 5 | System OK |
| 5 | Check for loose, missing, or damaged radiator air seals or deflectors. Are there any loose, missing, or damaged radiator air seals or deflectors? | Go to Step 6 | Go to Step 7 |
| 6 | Repair or replace any loose, missing, or damaged radiator air seals or deflectors. Does the engine still overheat? | Go to Step 7 | System OK |
| 7 | Check the coolant concentration. Does the coolant concentration test correctly? | Go to Step 9 | Go to Step 8 |
| 8 | Replace the coolant, if necessary. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Does the engine still overheat? | Go to Step 9 | System OK |
| 9 | IMPORTANT: Use the correct pressure cap. Check the system for loss of pressure.Is there a loss of pressure? | Go to Step 10 | Go to Step 11 |
| 10 | Repair any leaks, as necessary. Does the engine still overheat? | Go to Step 11 | System OK |
| 11 | Check for a faulty engine coolant temperature (ECT) sensor. Is the ECT sensor faulty? | Go to Step 12 | Go to Step 13 |
| 12 | Replace the ECT sensor. Refer to Engine Coolant Temperature Sensor Replacement . Does the engine still overheat? | Go to Step 13 | System OK |
| 13 | Check the radiator for any air flow obstructions or bent fins. Is there any airflow obstruction or bent fins? | Go to Step 14 | Go to Step 15 |
| 14 | Remove or relocate add-on parts that block air flow to the radiator. Clean any debris from the radiator core. Does the engine still overheat? | Go to Step 15 | System OK |
| 15 | Check for any blocked cooling system passages. Are there any blocked cooling system passages? | Go to Step 16 | Go to Step 17 |
| 16 | Remove any obstruction. Flush the cooling system as required. Refer to Flushing . Refill the coolant. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Does the engine still overheat? | Go to Step 17 | System OK |
| 17 | Check for an inoperative cooling fan. Is the cooling fan inoperative? | Go to Step 18 | Go to Step 19 |
| 18 | Replace the cooling fan. Refer to Cooling Fan and Shroud Replacement . Does the engine still overheat? | Go to Step 19 | System OK |
| 19 | Check for a thermostat that is stuck closed. Is the thermostat stuck closed? | Go to Step 20 | Go to Step 21 |
| 20 | Replace the thermostat. Refer to Thermostat Replacement (LNF) or Thermostat Replacement (LE5) . Does the engine still overheat? | Go to Step 21 | System OK |
| 21 | Check for a faulty water pump. The impeller blades may be eroded or broken. Is the water pump faulty? | Go to Step 22 | |
| 22 | Replace the water pump. Refer to Water Pump Replacement (LNF) or Water Pump Replacement (LE5) . Does the engine still overheat? | System OK | |
| IMPORTANT |
|---|
| Use the correct pressure cap. |
Engine Overheating
Loss of Coolant
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The cooling system is loosing 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 System Check - Vehicle . Is the action complete? | Go to Step 3 | |
| 3 | Inspect the coolant level. Is the coolant at the proper level? | Go to Step 6 | Go to Step 4 |
| 4 | Fill the cooling system to the proper level. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Is the action complete? | Go to Step 5 | |
| 5 | If the engine is suspected to have a coolant leak into a cylinder, the coolant can hydraulically lock the engine. Does the engine crankshaft rotate? | Go to Step 6 | Go to Step 26 |
| 6 | Engine overheating can cause a loss of coolant. Is the engine overheating? | Go to Step 27 | Go to Step 7 |
| 7 | Extended operation with a low coolant level can cause engine internal component failure. Is the engine knocking? | Go to Step 29 | 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 28 | Go to Step 10 |
| 10 | With the engine idling, inspect the surge tank. Does the surge tank 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: Coolant surge tank Heater core Radiator Are any of the hoses, clamps or pipes leaking? | Go to Step 20 | Go to Step 12 |
| 12 | Visually inspect the following components: The coolant pressure cap The core plugs The cylinder head gaskets The engine block The intake manifold The radiator The thermostat housing The water pump Are any of the listed components leaking? | Go to Step 20 | Go to Step 13 |
| 13 | Pressure test the cooling system. Refer to Cooling System Leak Testing . With the cooling system pressurized, visually inspect the components listed in steps 11 and 12. Are any leaks present? | Go to Step 20 | 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 21 |
| 15 | Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure? | Go to Step 30 | Go to Step 21 |
| 16 | Inspect for the following conditions: A coolant smell inside of the vehicle Coolant in the HVAC module drain tube Coolant on the vehicle floor covering near the HVAC module Is coolant present? | Go to Step 22 | Go to Step 17 |
| 17 | Inspect the underside of the engine oil fill cap for a gray/white milky substance. Is there a milky substance on under the oil fill cap? | Go to Step 18 | Go to Step 19 |
| 18 | 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 28 | Go to Step 19 |
| 19 | 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 23 | Go to Step 31 |
| 20 | Repair or replace the leaking component. Refer to the appropriate repair. Is the repair complete? | Go to Step 31 | |
| 21 | Replace the coolant pressure cap. Is the repair complete? | Go to Step 31 | |
| 22 | Replace the heater core. Refer to Heater Core Replacement . Is the repair complete? | Go to Step 31 | |
| 23 | 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? | Go to Step 24 | Go to Step 25 |
| 24 | Replace the radiator. Refer to Radiator Replacement . Service the automatic transmission. Refer to Engine Coolant/Water in Transmission for the 5L40-E/5L50-E transmission. Is the repair complete? | Go to Step 31 | |
| 25 | Install the cooler lines to the radiator. Is the action complete? | Go to Step 31 | |
| 26 | Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate . Is the repair complete? | Go to Step 31 | |
| 27 | Repair the engine overheating condition. Refer to Engine Overheating . Is the repair complete? | Go to Step 31 | |
| 28 | Repair the engine internal coolant leak. Refer to Coolant in Combustion Chamber or Coolant in Engine Oil . Is the repair complete? | Go to Step 31 | |
| 29 | Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed . Is the repair complete? | Go to Step 31 | |
| 30 | Repair the combustion pressure in the cooling system problem. Refer to Coolant in Combustion Chamber . Is the repair complete? | Go to Step 31 | |
| 31 | 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
Engine Fails To Reach Normal Operating Temperature
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Check the coolant level in the radiator surge tank. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Is the coolant at the proper level? | Go to Step 3 | Go to Step 2 | |
| 2 | Add coolant to the radiator surge tank as necessary. Does the engine still fail to reach normal operating temperatures? | Go to Step 3 | System OK | |
| 3 | Check for a blockage in the coolant passages. Are there any blockages in the coolant passages? | Go to Step 4 | Go to Step 5 | |
| 4 | Flush the cooling system or flow check the radiator. Refer to Flushing . Does the engine still fail to reach normal operating temperatures? | Go to Step 5 | System OK | |
| 5 | Check to see if the incorrect thermostat was installed or if it is stuck or sticks in the open position. Was the incorrect thermostat installed, or is it stuck or does it stick in the open position? | Go to Step 6 | ||
| 6 | Replace the thermostat. Refer to Thermostat Replacement (LNF) or Thermostat Replacement (LE5) . Does the engine still fail to reach normal operating temperature? | System OK |
Engine Fails To Reach Normal Operating Temperature
Tools Required
- J 26568 Coolant and Battery Fluid Tester. See «Special Tools»(ref-267956-S32146669372007101700000) .
- J 42401 Radiator Pressure Adapter. See «Special Tools»(ref-267956-S32146669372007101700000) .
Filling Procedure
- Close the radiator drain cock by hand.
- Install the water pump drain plug if removed during the draining process. Tighten: Tighten the plug to 22 N.m (16 lb ft).
- Lower the vehicle.
- Disconnect the coolant level sensor electrical connector.
- Remove and discard the surge tank retainer (2).
- Loosen surge tank nut (3).
- Raise and support surge tank approximately 350 mm (13.75 in) above the surge tank bracket.
- Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized water to the cooling system until the coolant level reaches and maintains slightly above the cold fill line on the surge tank. Refer to «Approximate Fluid Capacities»(ref-267964-S25304994402007101700000) .
- Position the surge tank back on the surge tank bracket.
- Install a new surge tank retainer (2).
- Install the surge tank nut (3). Tighten: Tighten the nut to 9 N.m (80 lb in).
- Connect the coolant level sensor electrical connector.
- Start the engine and idle.
- Install surge tank cap (1).
- Run the engine at 2,000-2,500 RPM for 3 minutes.
- Allow the engine to idle for 30 seconds.
- Shut the engine off.
- Top off the coolant as necessary.
- Inspect the cooling system for leaks.
- Rinse away any excess coolant from the engine and the engine compartment.
Radiator Cleaning
| CAUTION | NEVER spray water on a hot radiator. The resulting steam could cause personal injury. |
Note. The radiator 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.
- 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 17
| Callout | Component Name |
|---|---|
| NOTE: Refer to Fastener Notice . Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure IMPORTANT: Drain only the fluid from the radiator surge tank. Drain the cooling system. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Disconnect the surge tank sensor electrical connector. | |
| 1 | Cap Assembly, Radiator Surge Tank |
| 2 | Retainer, Radiator Surge Tank |
| 3 | Nut, Radiator Surge Tank Tighten: 9 N.m (80 lb in) |
| 4 | Tank Assembly, Radiator Surge Tip: Using J 38185 position radiator surge tank hose clamps aside and remove hoses from the radiator surge tank. See Special Tools . |
| NOTE |
|---|
| Refer to Fastener Notice . |
| IMPORTANT |
|---|
| Drain only the fluid from the radiator surge tank. |
Surge Tank Replacement
Scheme 18
| Callout | Component Name |
|---|---|
| NOTE: Refer to Fastener Notice . Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure: IMPORTANT: Position the surge tank to the side leaving the cooling system closed. Remove the surge tank. Refer to Surge Tank Replacement . | |
| 1 | Nut, Radiator Surge Tank Bracket Tighten: 9 N.m (80 lb in) |
| 2 | Bracket, Radiator Surge Tank Support |
| NOTE |
|---|
| Refer to Fastener Notice . |
| IMPORTANT |
|---|
| Position the surge tank to the side leaving the cooling system closed. |
Coolant Reservoir/Surge Tank Bracket Replacement
Scheme 19
| Callout | Component Name |
|---|---|
| NOTE: Refer to Fastener Notice . Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure: Drain the cooling system. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . | |
| 1 | Hose Assembly, Radiator Surge Tank Inlet Tip: Using J 38185 position radiator surge tank outlet hose clamps aside and remove hose from the fittings. See Special Tools . Note routing of the radiator surge tank inlet hose to ensure proper insulation. |
| NOTE |
|---|
| Refer to Fastener Notice . |
Surge Tank Hose/Pipe Replacement - Inlet
Scheme 20
| Callout | Component Name |
|---|---|
| NOTE: Refer to Fastener Notice . Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure Drain the cooling system. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Remove the air inlet grill panel. Refer to Air Inlet Grille Panel Replacement . | |
| 1 | Hose Assembly, Radiator Surge Tank Outlet Tip: Using J 38185 position radiator surge tank outlet hose clamps aside and remove hose from the fittings. See Special Tools . |
| NOTE |
|---|
| Refer to Fastener Notice . |
Surge Tank Hose/Pipe Replacement - Outlet
Scheme 21
| Callout | Component Name |
|---|---|
| NOTE: Refer to Fastener Notice . Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure Drain the cooling system. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Resonator Replacement . Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement . | |
| 1 | Hose Assembly, Radiator Inlet Tip: Using J 38185 position radiator inlet hose clamps aside and remove hose from the fittings. See Special Tools . |
| NOTE |
|---|
| Refer to Fastener Notice . |
Radiator Inlet Hose Replacement
Scheme 22
| Callout | Component Name |
|---|---|
| Preliminary Procedures Drain the cooling system. Refer to Draining and Filling Cooling System (GE-47716) or Draining and Filling Cooling System (2.4L LE5 Only) . Remove the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement . Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Resonator Replacement . Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement . | |
| 1 | Radiator Outlet Hose Assembly NOTE: Refer to Fastener Notice . Tip: Using J 38185 hose clamp pliers position radiator outlet hose clamps aside and remove hose from the fittings. See Special Tools . Remove radiator outlet hose push in retainer from the engine bracket and cradle. Note routing of the radiator outlet hose to ensure proper insulation. |
| NOTE |
|---|
| Refer to Fastener Notice . |
Radiator Outlet Hose Replacement
Scheme 23
| Callout | Component Name |
|---|---|
| NOTE: Refer to Fastener Notice . Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement . Remove the air cleaner duct. Refer to Air Cleaner Outlet Resonator Replacement . Disconnect the cooling fan motor electrical connector. | |
| 1 | Bolt, Radiator Assembly Tighten: 25 N.m (18 lb ft). |
| 2 | Shroud Assembly, Cooling Fan and Motor |
| NOTE |
|---|
| Refer to Fastener Notice . |
Cooling Fan and Shroud Replacement
J 43651 Water Pump Holding Tool. See Special Tools .
J 43651 Water Pump Holding Tool. See Special Tools .
Cooling Fan Control 2.0L
The engine cooling fan is a variable speed fan. The engine control module (ECM) controls the fan speed by sending a pulse width modulated (PWM) signal to the cooling fan control module. The cooling fan control module varies the voltage drop across the engine cooling fan motor in relation to the PWM signal. The cooling fan speed can be adjusted from 10 percent to 94 percent duty cycle. 94 percent is considered high speed fan.
The ECM commands fans ON under the following conditions
Fan Control During Engine Operation (Engine ON)
- Fixed 94 percent duty cycle commanded when the following conditions are met: Engine oil temperature is greater than 140°C (284°F). AT transmission temperature is greater than 140°C (284°F). Intake air temperature is greater than 65°C (149°F). Engine coolant temperature sensor faults have been detected (electrical or rational).
- Variable duty cycle from 15-95 percent is commanded when: From all available requests, the maximum requested duty cycle is selected and commanded. Dependent on engine coolant temperature, 0 percent up to 92.9°C (199.22°F). Then 15 percent at 93°C (199.4°F) to greater than 94 percent by 121°C (249.8°F). Dependent on A/C pressure sensor, 0 percent up to 10,979 hPa. Then 15 percent at 10,980 hPa to greater than 94 percent by 23,529 hPa. Fans commanded off during running operation when the above conditions are not met.
Fan Control During After-run (Engine OFF)
- Fixed 36 percent duty cycle commanded after shut-down when the engine coolant temperature at shut-down is greater 101°C (213°F).
- Fixed 60 percent duty cycle commanded after shut-down when the engine coolant temperature at shut-down is greater than 108°C (226.4°F).
- Fans commanded OFF during after-run when: System voltage is less than 11.5 V After-run time is greater than 420 seconds. Coolant temperature drops below a variable threshold.
Cooling Fan Control 2.4L
The engine cooling fan system consists of one cooling fan and two relays. The cooling fan has 2 windings in the motor, one winding is for low speed and the other winding is for high speed. Voltage is supplied to the relays through fuses. The engine control module (ECM) controls the low speed fan operation by grounding the cool fan 1 relay control circuit. When the cooling fan 1, which is the low speed relay, relay is energized, voltage is delivered to the cooling fan low speed winding. The ECM controls the high speed fan operation by grounding the cool fan 2 relay control circuit. When the cooling fan 2 relay, which is the high speed relay, is energized, voltage is delivered to the cooling fan high speed winding. The cooling fan motor is grounded through its own ground circuit.
The ECM commands low speed fans ON under the following conditions
- Engine coolant temperature (ECT) exceeds approximately 106°C (223°F).
- A/C refrigerant pressure exceeds 1,310 kPa (190 psi).
- After the vehicle is shut OFF, the ECT at key-off is greater than 140°C (284°F) and system voltage is more than 12 volts. The fans will stay ON for approximately 3 minutes.
The ECM commands high speed fans ON under the following conditions
- ECT reaches 110°C (230°F).
- A/C refrigerant pressure exceeds 1 655 kPa (240 psi).
- When certain DTCs set
When the request for fan activation is withdrawn, the fan may not turn OFF until the ignition switch is moved to the OFF position or the vehicle speed exceeds approximately 10 mph. This is to prevent a fan from cycling ON and OFF excessively at idle.
The engine cooling fan system consists of one cooling fan and two relays. The cooling fan has 2 windings in the motor, one winding is for low speed and the other winding is for high speed. Voltage is supplied to the relays from the 30 A cooling fan 1 and 30 A cooling fan 2 fuses. The engine control module (ECM) controls the low speed fan operation by grounding the cool fan 1 relay control circuit. When the cooling fan 1 relay is energized, voltage is delivered to the cooling fan low speed winding. The ECM controls the high speed fan operation by grounding the cool fan 2 relay control circuit. When the cooling fan 2 relay is energized, voltage is delivered to the cooling fan high speed winding. The cooling fan motor is grounded through its own ground circuit.
The PCM commands Low Speed Fans ON under the following conditions
- Engine coolant temperature (ECT) exceeds approximately 106°C (223°F).
- A/C refrigerant pressure exceeds 1 310 kPa (190 psi).
- After the vehicle is shut off, the ECT at key-off is greater than 140°C (284°F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes.
The PCM commands High Speed Fans ON under the following conditions
- ECT reaches 110°C (230°F).
- A/C refrigerant pressure exceeds 1 655 kPa (240 psi).
- When certain DTCs set
LOW COOLANT LEVEL
The IPC illuminates the low coolant warning indicator when any of the following occur
- The BCM detects a low coolant level condition for at least 30 seconds. The IPC receives a class 2 message from the BCM requesting illumination.
- The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
Coolant Heater
The optional engine coolant heater (RPO K05) 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 -29°C (-20°F). The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.
The cooling system's function is to maintain an efficient engine operating temperature during all engine speeds and operating conditions. The cooling system is designed to remove approximately one-third of the heat produced by the burning of the air-fuel mixture. When the engine is cold, the coolant does not flow to the radiator until the thermostat opens. This allows the engine to warm quickly.
Charge Air Cooling System (LSJ Only)
The charge air cooling systems function is to reduce the temperature of the air charge that is heated during the supercharging process which improves the efficiency of the supercharging system. The charge air cooling system is a water-to-air system that uses a dedicated electric coolant pump, a modified intake manifold, and a separate charge air cooling radiator located between the condenser and the radiator to cool the air charge.
Cooling Cycle
Coolant flows from the radiator outlet and into the water pump inlet. Some coolant flows from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost capability as the coolant warms up.
Coolant also flows from the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.
The coolant then flows through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.
From the cylinder heads, the coolant flows to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine reaches normal operating temperature, or it will flow through the thermostat and into the radiator where it is cooled. At this point, the coolant flow cycle is completed.
Efficient operation of the cooling system requires proper functioning of all cooling system components. The cooling system consists of the following components
Coolant
The engine coolant is a solution made up of a 50-50 mixture of DEX-COOL and suitable drinking water. The coolant solution carries excess heat away from the engine to the radiator, where the heat is dissipated to the atmosphere.
Radiator
The radiator is a heat exchanger. It consists of a core and two tanks. The aluminum core is a tube and fin crossflow design that extends from the inlet tank to the outlet tank. Fins are placed around the outside of the tubes to improve heat transfer to the atmosphere.
The inlet and outlet tanks are a molded, high temperature, nylon reinforced plastic material. A high temperature rubber gasket seals the tank flange edge to the aluminum core. The tanks are clamped to the core with clinch tabs. The tabs are part of the aluminum header at each end of the core.
The radiator also has a drain cock located in the bottom of the right hand tank. The drain cock unit includes the drain cock and drain cock seal.
The radiator removes heat from the coolant passing through it. The fins on the core transfer heat from the coolant passing through the tubes. As air passes between the fins, it absorbs heat and cools the coolant.
Pressure Cap
The pressure cap seals the cooling system. It contains a blow off or pressure valve and a vacuum or atmospheric valve. The pressure valve is held against its seat by a spring, which protects the radiator from excessive cooling system pressure. The vacuum valve is held against its seat by a spring, which permits opening of the valve to relieve vacuum created in the cooling system as it cools off. The vacuum, if not relieved, might cause the radiator and/or coolant hoses to collapse.
The pressure cap allows cooling system pressure to build up as the temperature increases. As the pressure builds, the boiling point of the coolant increases. 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 is, the faster the heat transfers from the radiator to the cooler, passing air.
The pressure in the cooling system can get too high. When the cooling system pressure exceeds the rating of the pressure cap, it raises the pressure valve, venting the excess pressure.
As the engine cools down, the temperature of the coolant drops and a vacuum is created in the cooling system. This vacuum causes the vacuum valve to open, allowing outside air into the surge tank. This equalizes the pressure in the cooling system with atmospheric pressure, preventing the radiator and coolant hoses from collapsing.
Surge Tank
The surge tank is a plastic tank that the pressure cap mounts onto. The tank is mounted at a point higher than all other coolant passages. The surge tank provides an air space in the cooling system. The air space allows the coolant to expand and contract. The surge tank also provides a coolant fill point and a central air bleed location. During vehicle use, the coolant heats and expands. The coolant that is displaced by this expansion flows into the surge tank. As the coolant circulates, air is allowed to exit. This is an advantage to the cooling system. Coolant without bubbles absorbs heat much better than coolant with bubbles.
Air Baffles and Seals
The cooling system uses deflectors, air baffles and air seals to increase cooling system capability. Deflectors are installed under the vehicle to redirect airflow beneath the vehicle and through the radiator to increase engine cooling. Air baffles are also used to direct airflow through the radiator and increase cooling capability. Air seals prevent air from bypassing the radiator and A/C condenser, and prevent recirculation of hot air for better hot weather cooling and A/C condenser performance.
Water Pump
The water pump is a centrifugal vane impeller type pump. The pump consists of a housing with coolant inlet and outlet passages and an impeller. The impeller is mounted on the pump shaft and consists of a series of flat or curved blades or vanes on a flat plate. When the impeller rotates, the coolant between the vanes is thrown outward by centrifugal force.
The impeller shaft is supported by one or more sealed bearings. The sealed bearings never need to be lubricated. Grease cannot leak out, dirt and water cannot get in as long as the seal is not damaged or worn.
The purpose of the water pump is to circulate coolant throughout the cooling system. The water pump is driven by the crankshaft via the timing chain.
Thermostat
The thermostat is a coolant flow control component. It's purpose is to help regulate the operating temperature of the engine. It utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a small piston. When the element is heated, it expands and exerts pressure against the small piston. This pressure forces the valve to open. As the element is cooled, it contracts. This contraction allows a spring to push the valve closed.
When the coolant temperature is below the rated thermostat opening temperature, the thermostat valve remains closed. This prevents circulation of the coolant to the radiator and allows the engine to warm up. After the coolant temperature reaches the rated thermostat opening temperature, the thermostat valve will open. The coolant is then allowed to circulate through the thermostat to the radiator where the engine heat is dissipated to the atmosphere. The thermostat also provides a restriction in the cooling system, after it has opened. This restriction creates a pressure difference which prevents cavitation at the water pump and forces coolant to circulate through the engine block.
Transmission Oil Cooler
The transmission oil cooler is a heat exchanger. It is located inside the left side end tank of the radiator. The transmission fluid temperature is regulated by the temperature of the engine coolant in the radiator.
The transmission oil pump, pumps the fluid through the transmission oil cooler line to the transmission oil cooler. The fluid then flows through the cooler where the engine coolant absorbs heat from the fluid. The fluid is then pumped through the transmission oil cooler return line, to the transmission.