Engine Cooling System Cadillac DTS I

Fastener Tightening Specifications

Scheme 1

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Engine Cooling

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

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

In low speed operation, the ECM applies ground to the coil side of the low speed relay, which is R1 cool/fan 1 relay. Voltage is applied directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to the left fan through the de-energized series/parallel relay, which is R7 cool/fan 2 relay, so that both fans operate at low speed.

In high speed operation, the ECM applies a ground to the coil side of the low speed relay, the R2 cool/fan series/parallel relay, and the high speed relay, which is relay R2 cool/fan relay. Voltage is applied directly to the right cooling fan through the switch side of the high speed relay. The left cooling fan obtains voltage through the low speed relay and ground through the series/parallel relay.

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

Conditions for Running the DTC

1. The ignition is ON.
2. The system voltage is between 9-18 volts.
3. The relay control circuit is transitioned from OFF to ON or ON to OFF.

P0480

The ECM detects an open circuit in the low speed cooling fan relay control circuit.

P0481

1. The ECM detects an open circuit in the high speed cooling fan relay control circuit.
2. The above condition is present for 30 seconds.

Action Taken When the DTC Sets

DTCs P0480 and P0481 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0480 and P0481 are Type B DTCs.

Reference Information

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Engine Control Module Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Probing Electrical Connectors»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__probing-electrical-connectors)
6. «Electrical Center Identification Views»(/cadillac/dts/i-2005-2011/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-component-connector-end-views)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tools Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers

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.

Circuit/System Testing

1. Ignition OFF, disconnect the R2 cool/fan relay.
2. Connect a 30A fused jumper between the normally-open switch contact terminals at the R2 cool/fan relay connector in order to complete the fan ground circuit. Leave this jumper in place for the remainder of this procedure.
3. Ignition OFF, disconnect the affected relay.
4. Verify that a test lamp does not illuminate between B+ and the affected relay control circuit terminal.
5. Remove the test lamp.
6. Command the affected relay ON with a scan tool. Verify the scan tool Relay Control Ckt. Short Volts Test Status parameter is OK. If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
7. Install a 3A fused jumper wire between the control circuit terminal and B+. Command the affected relay ON with a scan tool. Verify the scan tool Relay Control Ckt Short Volts Test Status parameter is Fault. If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
8. Remove the 3A fused jumper wire.
9. Connect a 30A fused jumper between the positive voltage terminal at the battery and the fan voltage supply circuit terminal at the affected relay connector and verify fan activation. If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fan.
10. Ignition ON, connect a 30A fused jumper between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal at the affected relay connector and verify fan activation. If the fan does not activate, test the affected relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary.
11. Ignition ON, verify that a test lamp illuminates between the affected relay coil voltage supply circuit terminal and ground. If the test lamp does not illuminate, test the affected relay coil voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary.
12. If all circuits and the ECM test normal, replace the affected relay.

Repair 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.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) or powertrain control module (PCM) uses the engine coolant temperature (ECT) sensor to monitor the engine for an overtemperature condition. This condition occurs when the coolant temperature is above a calibrated value for a calibrated length of time. The ECM or PCM will disable half of the cylinders by turning OFF the fuel injectors. By disabling half of cylinders, the ECM or PCM is able to reduce the temperature of the coolant.

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

Conditions for Setting the DTC

Coolant temperature more than 131°C (267.8°F) for more than 7 seconds.

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

DTC P1258 is a Type A DTC.

Description and Operation

1. «Cooling Fan Description and Operation»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Instrument Cluster Description and Operation»(/cadillac/dts/i-2005-2011/remont/gauges-instrument-panels/#instrument-panel-system-displays-gages)
3. «Indicator/Warning Message Description and Operation»(/cadillac/dts/i-2005-2011/remont/gauges-instrument-panels/#instrument-panel-system-displays-gages__indicatorwarning-message-description-operation)
4. «Audible Warnings Description and Operation»(/cadillac/dts/i-2005-2011/remont/gauges-instrument-panels/#instrument-panel-system-displays-gages__audible-warnings-description-operation)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Observe the engine coolant level. The engine coolant level should be within operating range. Refer to Capacities - Approximate Fluid, and Engine Coolant in the Owner's Manual.
2. Ensure that the vehicle has the correct engine coolant, with correct concentration, and is not old, contaminated or contains additives. Refer to Recommended Fluids and Lubricants in the Owner's Manual.
3. Inspect the cooling system for the following: Cooling system leaks Kinked or pinched hoses, especially at the radiator Loose, missing, or damaged radiator air seals or deflectors The radiator and A/C condenser for any air flow obstructions or bent fins-Refer to «Symptoms - Engine Cooling»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__symptoms-engine-cooling) .
4. Command the cooling fans in both low and high speed. If the cooling fans do not operate in both speeds, refer to «Cooling Fan Inoperative»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Test the thermostat for correct operation. Refer to «Thermostat Diagnosis»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Test the engine cooling system for overheating. Refer to «Engine Overheating»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating) .
3. Inspect the water pump and coolant flow for correct operation. Refer to «Water Pump Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Inspect the engine mechanical for worn/leaking/cracked cylinder heads and engine block. Refer to «Coolant in Combustion Chamber»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5__coolant-in-combustion-chamber) .

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Symptoms - Engine Cooling

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Cooling System. Refer to «Checking Aftermarket Accessories»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect the surge tank reservoir for the proper coolant level.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

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

1. «Cooling Fan Always On»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Cooling Fan Inoperative»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
3. «Engine Overheating»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating)
4. «Loss of Coolant»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant)
5. «Thermostat Diagnosis»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
6. «Engine Fails To Reach Normal Operating Temperature»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__engine-fails-to-reach-normal-operating)
7. «Pressure Cap Testing»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__pressure-cap-testing)
8. «Cooling System Leak Testing»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-leak-testing)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of the diagnostic category.

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

In low speed operation, the ECM applies ground to the coil side of the low speed relay, which is R1 cool/fan 1 relay. Voltage is applied directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to the left fan through the de-energized series/parallel relay, which is R7 cool/fan 2 relay, so that both fans operate at low speed.

In high speed operation, the ECM applies a ground to the coil side of the low speed relay, the R2 cool/fan series/parallel relay, and the high speed relay, which is relay R2 cool/fan relay. Voltage is applied directly to the right cooling fan through the switch side of the high speed relay. The left cooling fan obtains voltage through the low speed relay and ground through the series/parallel relay.

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

Schematic Reference

1. «Engine Cooling Schematics»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Electrical Center Identification Views»(/cadillac/dts/i-2005-2011/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-component-connector-end-views)

Connector End View Reference

Component Connector End Views

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

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

1. Ignition OFF, disconnect the relays.
2. Ignition ON, observe that the fan is not activated. If the fan is not activated, then replace the faulty relay. If the fan is activated, then test the fan voltage supply circuits for a short to voltage.

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

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of the diagnostic category.

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

In low speed operation, the ECM applies ground to the coil side of the low speed relay, which is R1 cool/fan 1 relay. Voltage is applied directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to the left fan through the de-energized series/parallel relay, which is R7 cool/fan 2 relay, so that both fans operate at low speed.

In high speed operation, the ECM applies a ground to the coil side of the low speed relay, the R2 cool/fan series/parallel relay, and the high speed relay, which is relay R2 cool/fan relay. Voltage is applied directly to the right cooling fan through the switch side of the high speed relay. The left cooling fan obtains voltage through the low speed relay and ground through the series/parallel relay.

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

Schematic Reference

1. «Engine Cooling Schematics»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Electrical Center Identification Views»(/cadillac/dts/i-2005-2011/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-component-connector-end-views)

Connector End View Reference

Component Connector End Views

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. If DTCs P0480 or P0481 are set, then perform those diagnostics first.
2. 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.

1. Ignition OFF, disconnect the R2 cool/fan relay.
2. Ignition ON, activate the cooling fan relay 1 with the scan tool. The fan should be OFF. If the fan is activated, test the left fan ground circuit for a short to ground.
3. Ignition OFF, disconnect the fan relays.
4. Connect a 30A fused jumper between the normally-open switch contact terminals at the R2 cool fan relay connector in order to complete the left fan ground circuit. Leave this jumper in place for the remainder of this procedure.
5. One at a time, connect a 30A fused jumper between the positive terminal at the battery and the fan voltage supply circuit terminal at the cool/fan 1 and the cool/fan 2 relay connections and verify fan activation. If the appropriate fan does not activate, test the fan voltage supply circuit for a short to ground or open/high resistance. If the circuit tests normal, test the fan ground circuit for an open/high resistance. If the circuits test normal, replace the fan.
6. Ignition ON, connect a 30A fused jumper between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal at the cool/fan 1 and the cool/fan 2 relay connections and verify fan activation. If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary.
7. If the circuits and fans test normal, replace the relay.

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.

Engine Overheating

Loss of Coolant

Tools Required

J 24731 Tempilstick. See Special Tools .

The coolant thermostat can be tested using a temperature (tempil) stick. The temperature stick is a pencil like device. It has a wax material containing certain chemicals which 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 thermostat housing.

1. Use a tempilstick in order to find the opening and the closing temperatures of the coolant thermostat. J 24731 -188 tempilstick melts at 87°C (188°F). See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . The thermostat should begin to open. J 24731 -206 tempilstick melts at 97°C (206°F). See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . The thermostat should be fully open.
2. Replace the coolant thermostat if it does not operate properly between this temperature range. Refer to «Engine Coolant Thermostat Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/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»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Engine Coolant Heater Replacement - Left Side»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Engine Coolant Heater Replacement - Right Side»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)
3. «Coolant Heater Cord Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Fails To Reach Normal Operating Temperature

Pressure Cap Testing

Tools required

1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 42401 Radiator Cap/Surge Tank Test Adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

Test Procedure

1. Remove the pressure cap.
2. Wash the pressure cap sealing surface with water.
3. Use the J 24460-01 (1) with J 42401 (2) in order to test the pressure cap. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
4. Test the pressure cap for the following conditions: Pressure release when the J 24460-01 exceeds the pressure rating of the pressure cap. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . 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.

Cooling System Leak Testing

Tools Required

1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 42401 Radiator Cap/Surge Tank Test Adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Remove the pressure cap.
2. Test the operation of the pressure cap. Refer to «Pressure Cap Testing»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__pressure-cap-testing) .
3. Wash the pressure cap mating surface with water.
4. Use the J 24460-01 (1) with J 42401 (2) in order to apply pressure to the cooling system. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Do not exceed the pressure cap rating.
5. The cooling system should hold the rated pressure for at least 2 minutes. Observe the gauge for any pressure loss.
6. Repair any leaks as required.

Cooling System Draining & Filling (Vac-N-Fill)

Tools Required

1. J 26568 Coolant and Battery Fluid Tester. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 38185 Hose Clamp Pliers. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
3. J 42401 Radiator Cap and Surge Tank Test Adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
4. GE-47716 Vac N Fill Coolant Refill Tool. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

Draining Procedure

1. Park the vehicle on a level surface.
2. Remove the surge tank cap.
3. Remove the air box. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
5. Remove the air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bumper-system-fascia) .
6. Lower the vehicle.
7. Place a drain pan under the lower radiator hose connection.
8. Using the J 38185 reposition the lower radiator hose clamp away from the radiator. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
9. Slowly remove the lower radiator hose and drain the coolant into the drain pan.
10. Inspect the engine coolant for the following conditions: Discolored appearance-Follow the flush procedure. Refer to «Flushing»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__flushing) . Normal in appearance-Follow the filling procedure.

Vac-N-Fill Procedure

1. Install the J 42401 onto the coolant surge tank. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. Attach the Vac N Fill cap to the vehicle's coolant fill port.
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 the overflow hose closed.
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. Monitor for vacuum loss. If vacuum loss is observed, refer to «Loss of Coolant»(/cadillac/dts/i-2005-2011/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 12-18.
20. Detach the Vac N Fill cap from the vehicle's coolant fill port.
21. Remove the J 42401 from the coolant surge tank. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
22. Add coolant to the system as necessary.
23. Use the J 26568 to inspect the concentration of the coolant mixture using. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
24. Detach the vacuum hose from the vacuum gauge assembly.
25. Attach the extraction hose to the vacuum hose.
26. Open the valve on the venturi assembly to start a vacuum draw.
27. Use the extraction hose to draw out coolant to the proper level.
28. 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.
29. Install the surge tank cap.

Cooling System Draining & Filling (Static Fill)

Tools Required

1. J 26568 Coolant and Battery Fluid Tester. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 38185 Hose Clamp Pliers. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Park the vehicle on a level surface.
2. Remove the surge tank cap.
3. Remove the air box. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
5. Remove the air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bumper-system-fascia) .
6. Lower the vehicle.
7. Place a drain pan under the lower radiator hose connection.
8. Using the J 38185 reposition the lower radiator hose clamp away from the radiator. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
9. Slowly remove the lower radiator hose. Drain the coolant into the drain pan.
10. Inspect the engine coolant for the following conditions: Discolored appearance-Follow the flush procedure. Refer to «Flushing»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__flushing) . Normal in appearance-Follow the filling procedure.

Filling Procedure

Note. The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.

1. Install the lower radiator hose.
2. Using the J 38185 reposition the lower radiator hose clamp to the radiator. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
3. Lower the vehicle.
4. Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized water to the cooling system through the top of the surge tank opening. Refer to «Approximate Fluid Capacities»(/cadillac/dts/i-2005-2011/remont/lubrication-system/#maintenance-and-lubrication__approximate-fluid-capacities) .
5. Fill the surge tank to the FULL COLD level.
6. Install the surge tank cap.
7. Idle the engine for 2 minutes and occasionally raise the throttle to 3,000-3,500 RPM.
8. Turn off the engine and allow the engine to cool.
9. Repeat the steps 3-7.
10. Install the air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bumper-system-fascia) .
11. Install the air box. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
12. Allow the engine to cool.
13. Remove the surge tank cap and fill to the FULL COLD level.
14. Use the J 26568 to inspect the concentration of the engine coolant. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
15. Rinse away any excess coolant from the engine and the engine compartment.

Flushing

Various methods and equipment may be used to flush the system. If using special equipment such as a back flusher, follow the manufacturer's instructions.

Radiator Cleaning

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.

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

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

DT-47731 1/2 Inch Quick Connect Release Tool. See Special Tools .

Removal Procedure

1. Remove the radiator assembly. Refer to «Radiator Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the engine oil cooler inlet line (2) from the engine oil filter adaptor using DT-47731 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
3. Remove the engine oil cooler outlet line (1) from the engine oil filter adaptor.
4. Remove the engine oil cooler lines from the vehicle.

Installation Procedure

1. Install the engine oil cooler lines to the vehicle.
2. Install the engine oil cooler outlet line (1) to the engine oil filter adaptor.
3. Install the engine oil cooler inlet line (2) to the engine oil filter adaptor.
4. Install the radiator assembly. Refer to «Radiator Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Inspect the engine oil level.

1. Remove the cooling fan shroud assembly. Refer to «Fan Shroud Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__fan-shroud-replacement) .
2. Remove the cooling fan blade retaining nut.
3. Remove the cooling fan blade.

1. Install the cooling fan blade.
2. Install the cooling fan retaining nut. Tighten: Tighten the nut to 6 N.m (53 lb in).
3. Install the cooling fan shroud assembly. Refer to «Fan Shroud Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__fan-shroud-replacement) .

1. Remove the cooling fan assembly. Refer to «Fan Shroud Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__fan-shroud-replacement) .
2. Remove the cooling fan. Refer to «Engine Cooling Fan Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the cooling fan motor retaining bolts.
4. Remove the cooling fan motor from the fan shroud.

1. Install the cooling fan motor to the fan shroud.
2. Install the cooling fan motor retaining bolts. Tighten: Tighten the bolts to 6 N.m (53 lb in).
3. Install the cooling fan. Refer to «Engine Cooling Fan Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Install the cooling fan assembly. Refer to «Fan Shroud Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__fan-shroud-replacement) .

J 38185 Hose Clamp Pliers. See Special Tools .

1. Remove the air cleaner. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. Drain the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
3. Using the J 38185 , reposition the radiator outlet hose clamp (1) at the thermostat housing. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
4. Remove the radiator outlet hose (2) from the thermostat housing.
5. Remove the thermostat housing bolts.
6. Remove the thermostat housing, thermostat, and gasket from the water pump housing.
7. Discard the old thermostat housing gasket.

1. Install a NEW thermostat housing gasket into the water pump housing.
2. Install the thermostat into the water pump housing.
3. Install the thermostat housing.
4. Install the thermostat housing bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
5. Install the radiator outlet hose (2) to the thermostat housing.
6. Using the J 38185 , position the radiator outlet hose clamp (1) at the thermostat housing. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
7. Fill the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
8. Install the air cleaner. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

J 38185 Hose Clamp Pliers. See Special Tools .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
2. Remove the air cleaner. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-2-of-5) .
4. Remove the water pump drive belt. Refer to «Water Pump Belt Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Reposition the brake booster vacuum hose clamp at the water pump housing.
6. Remove the brake booster vacuum hose from the water pump housing.
7. Remove the oil level indicator tube nut.
8. Reposition the oil level indicator tube.
9. Remove the transaxle vent hose clip (1) from the bracket.
10. Remove the throttle body bolts.
11. Remove the bracket.
12. Remove the throttle body.
13. Remove and discard the throttle body seal.
14. Loosen the throttle body plenum duct clamp.
15. Remove and discard the throttle body plenum duct.
16. Remove the fuel rail bracket nut at the rear left lift bracket.
17. Reposition the surge tank inlet hose clamp at the fitting.
18. Remove the surge tank inlet hose from the fitting.
19. Remove the engine coolant outlet fitting.
20. Remove the rear left lift bracket bolt.
21. Remove the rear left lift bracket.
22. Remove the exhaust gas recirculation (EGR) valve shield nuts.
23. Remove the EGR valve shield.
24. Remove the EGR valve bolts.
25. Remove the EGR valve.
26. Remove and discard the EGR valve gasket.
27. Disconnect the engine harness electrical connector (1) from the engine valley electrical connector.
28. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
29. Disconnect the EGR inlet pipe nut from the exhaust manifold front pipe.
30. Lower the vehicle.
31. Remove the EGR inlet pipe bolt from the water pump housing.
32. Remove and discard the EGR inlet pipe.
33. Remove the evaporative emission (EVAP) canister purge solenoid valve bolt.
34. Remove the EVAP canister purge solenoid valve.
35. Remove the manifold absolute pressure (MAP) sensor bracket bolt.
36. Remove the MAP sensor bracket.
37. Remove the MAP sensor.
38. Using the J 38185 , reposition the radiator inlet hose clamp (1) at the water pump housing. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
39. Remove the radiator inlet hose (2) from the water pump housing.
40. Using the J 38185 , reposition the radiator outlet hose clamp (1) at the thermostat housing. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
41. Remove the radiator outlet hose (2) from the thermostat housing.
42. Remove the water pump belt tensioner studs.
43. Remove the water pump belt tensioner.
44. Reposition the heater outlet hose clamp (4) at the heater pipe.
45. Remove the heater outlet hose (3) from the heater pipe.
46. Remove the water pump cover bolt and studs.
47. Remove the water pump cover
48. Loosen the water pump housing bolts.
49. Remove the water pump housing.
50. Remove the water pump housing gaskets and bolts.
51. With the water pump housing on the bench, remove the water pump bolts.
52. Remove the water pump from the water pump housing.
53. Remove and discard the water pump O-ring.

1. Install a NEW water pump O-ring to the water pump.
2. Install the water pump.
3. Install the water pump bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
4. With the water pump housing on the bench, install the bolts in the locations shown. Bolt (1) length 40.7 mm (1.6024 in). Bolts (2) length 92.0 mm (3.6220 in). Bolts (3) length 109.0 mm (4.2913 in). Bolts (4) length 115.0 mm (4.5276 in).
5. With the housing still on the bench, install the NEW water pump housing gasket onto the bolts.
6. Position the water pump housing to the engine and hand start the bolts.
7. Tighten the water pump housing bolts. Tighten: Tighten the bolts in the sequence shown to 25 N.m (18 lb ft).
8. Install the water pump cover.
9. Install the water pump cover bolt and studs. Tighten: Tighten the bolt/studs to 10 N.m (89 lb in).
10. Install the heater outlet hose (3) to the heater pipe.
11. Position the heater outlet hose clamp (4) at the heater pipe.
12. Position the water pump belt tensioner.
13. Install the water pump belt tensioner studs. Tighten: Tighten the studs to 10 N.m (89 lb in).
14. Install the radiator outlet hose (2) to the thermostat housing.
15. Using the J 38185 , position the radiator outlet hose clamp (1) at the thermostat housing. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
16. Install the radiator inlet hose (2) to the water pump housing.
17. Using the J 38185 , position the radiator inlet hose clamp (1) at the water pump housing. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
18. Install the MAP sensor.
19. Install the MAP sensor bracket.
20. Install the MAP sensor bracket bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
21. Install the EVAP canister purge solenoid valve.
22. Install the EVAP canister purge solenoid valve bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
23. Hand start the NEW EGR inlet pipe nut at the exhaust manifold front pipe.
24. Install the EGR inlet pipe and bolt to the water pump housing. Tighten: Tighten the nut to 60 N.m (44 lb ft). Tighten the bolt to 25 N.m (18 lb ft).
25. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
26. Tighten the EGR inlet pipe nut. Tighten: Tighten the nut to 60 N.m (44 lb ft).
27. Lower the vehicle.
28. Connect the engine harness electrical connector (1) to the engine valley electrical connector.
29. Install the NEW EGR valve gasket.
30. Install the EGR valve.
31. Install the EGR valve bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
32. Install the EGR valve shield.
33. Instal the EGR valve shield nuts. Tighten: Tighten the nuts to 10 N.m (89 lb in).
34. Position the rear left lift bracket to the water pump housing.
35. Install the rear left lift bracket bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
36. Install the engine coolant outlet fitting. Tighten: Tighten the fitting to 47 N.m (35 lb ft).
37. Install the surge tank inlet hose to the fitting.
38. Position the surge tank inlet hose clamp at the fitting.
39. Instal the fuel rail bracket nut (2) at the rear left lift bracket. Tighten: Tighten the nut to 10 N.m (89 lb in).
40. Install a NEW throttle body plenum duct.
41. Tighten the throttle body plenum duct clamp. Tighten: Tighten the clamp to 2.25 N.m (20 lb in).
42. Install a NEW throttle body seal.
43. Install the throttle body.
44. Install the throttle body bracket.
45. Install the throttle body bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
46. Install the transaxle vent hose clip (1) to the bracket.
47. Position the oil level indicator tube.
48. Install the oil level indicator tube nut. Tighten: Tighten the nut to 10 N.m (89 lb in).
49. Install the brake booster vacuum hose to the water pump housing.
50. Position the brake booster vacuum hose clamp at the water pump housing.
51. Install the water pump drive belt. Refer to «Water Pump Belt Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
52. Install the air cleaner. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
53. Fill the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
54. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-2-of-5) .

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-2-of-5) .
2. Remove the water pump drive belt tensioner shield bolt/nuts.
3. Remove the water pump drive belt tensioner shield.

1. Install the water pump drive belt tensioner shield onto the studs.
2. Install the water pump drive belt tensioner shield bolt/nuts. Tighten: Tighten the bolt/nuts to 10 N.m (89 lb in).
3. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-2-of-5) .

Water Pump Pulley Replacement

Tools Required

1. J 38825 Power Steering and Water Pump Pulley Remover
2. J 38823 Water Pump Pulley Installer. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Release the outer water pump drive belt tensioner and remove the drive belt from the drive pulley. Refer to «Water Pump Belt Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the end cap from the intake camshaft.
3. Remove the water pump drive pulley from the intake camshaft using the J 38825 .

1. Place the water pump drive pulley in position on the intake camshaft.
2. Install the water pump pulley onto the intake camshaft using the J 38823 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . During installation, the tool will bottom out on the camshaft at the proper depth.
3. Install the camshaft end cap. Tighten: Tighten the cap to 2 N.m (18 lb in).
4. Install the water pump drive belt. Refer to «Water Pump Belt Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the water pump drive belt. Refer to «Water Pump Belt Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the water pump drive belt tensioner studs.
3. Remove the water pump drive belt tensioner.

1. Position the water pump drive belt tensioner to the water pump housing.
2. Install the water pump drive belt tensioner studs. Tighten: Tighten the studs to 10 N.m (89 lb in).
3. Install the water pump drive belt. Refer to «Water Pump Belt Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the water pump drive belt tensioner. Refer to «Drive Belt Tensioner Replacement - Water Pump»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the water pump drive belt (1) by sliding the belt off of the drive pulley (3) and water pump pulley.

1. Route the water pump drive belt (1) around the water pump pulley and the water pump drive pulley (3).
2. Install the water pump drive belt tensioner. Refer to «Drive Belt Tensioner Replacement - Water Pump»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Check the drive belt for proper seating in all the pulley grooves.

1. Remove the water pump housing. Refer to «Engine Coolant Crossover Pipe Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the water pump cover bolt/studs.
3. Remove the water pump cover.
4. Remove the water pump bolts.
5. Remove the water pump.
6. Remove and discard the water pump O-ring seal.

1. Install a NEW water pump O-ring seal.
2. Install the water pump.
3. Install the water pump bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
4. Remove the water pump cover.
5. Remove the water pump cover bolt/studs. Tighten: Tighten the bolt/studs to 10 N.m (89 lb in).
6. Install the water pump housing. Refer to «Engine Coolant Crossover Pipe Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

Fan Shroud Replacement

Tools Required

1. J 38185 Hose Clamp Plier. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 41623-B Trans Oil Cooler Line Disconnect. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnection and Connection»(/cadillac/dts/i-2005-2011/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the condenser. Refer to «Condenser Replacement»(/cadillac/dts/i-2005-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. Remove the upper tie bar. Refer to «Front End Upper Tie Bar Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
4. Drain the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
5. Remove the front air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bumper-system-fascia) .
6. Remove the engine oil cooler pipe retaining bolts (1, 2) from the fan shroud if equipped.
7. Lower the vehicle.
8. Using J 38185 reposition the radiator inlet hose clamp. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
9. Disconnect the radiator inlet hose from the radiator.
10. Remove the transmission oil cooler pipe retaining bolts from the fan shroud.
11. Remove the transmission lines from the radiator. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(/cadillac/dts/i-2005-2011/remont/automatic-trans/#how-to-overhaul-the-automatic-transaxle-4t80-e-removal-installation-service-troubleshooting-diagnosis) .
12. Disconnect the wiring harness electrical connectors (1) from the cooling fan motors.
13. Remove the clips (2) attaching the harness to the fan shroud.
14. Remove the electric cooling fan mounting bolts.
15. Remove the electric cooling fan assembly from the vehicle in the following order: Position the cooling fan assembly towards the left side of the vehicle. Pull upward on the right side of the fan assembly. Position the fan assembly towards the right side of the vehicle. Pull upward on the fan assembly removing the fan assembly from the vehicle.

1. Install the cooling fan assembly to the vehicle in the following order: Position the cooling fan assembly behind the radiator. Position the fan assembly towards the right side of the vehicle. Push downward on the right side of the fan assembly. Move the fan assembly into position, aligning the lower feet of the fan shroud to the mounting tabs on the radiator.
2. Install the electric cooling fan mounting bolts. Tighten: Tighten the bolts to 6 N.m (53 lb in).
3. Connect the wiring harness electrical connectors (1) to the cooling fan motors.
4. Attach the wiring harness retaining clips (2) to the fan shroud.
5. Push the upper transaxle oil cooler pipe into the radiator quick connect fitting, until a "click" is heard.
6. Tug gently on the cooler pipe to ensure proper retention.
7. Slide the plastic cap (1) over the quick connect joint.
8. Install the transmission oil cooler pipe retaining bolts to the fan shroud. Tighten: Tighten the bolts to 6 N.m (53 lb in).
9. Install the radiator inlet hose to the radiator.
10. Using J 38185 reposition the radiator inlet hose clamp. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
11. Raise the vehicle.
12. Install the engine oil cooler pipe retaining bolts (1, 2) to the fan shroud. Tighten: Tighten the bolts to 6 N.m (53 lb in).
13. Install the front air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bumper-system-fascia) .
14. Lower the vehicle.
15. Install the condenser. Refer to «Condenser Replacement»(/cadillac/dts/i-2005-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
16. Install the upper tie bar. Refer to «Front End Upper Tie Bar Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
17. Fill the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
18. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnection and Connection»(/cadillac/dts/i-2005-2011/remont/charging-system/#battery-charging-system-and-starting-system) .
19. Inspect the engine oil level.

J 38185 Hose Clamp Pliers. See Special Tools .

1. Remove the cooling fan shroud assembly. Refer to «Fan Shroud Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__fan-shroud-replacement) .
2. Lift the radiator up and out the vehicle.

1. Install the radiator to the vehicle.
2. Position the condenser, aligning the lower feet to the lower mounting features located at the front of the radiator.
3. Install the condenser mounting bolts. Tighten: Tighten the bolts to 13 N.m (115 lb in).
4. Install the fan shroud assembly. Refer to «Fan Shroud Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__fan-shroud-replacement) .

1. Remove the radiator support bracket retaining bolt.
2. Remove the radiator support bracket.

1. Install the radiator support bracket.
2. Install the radiator support bracket retaining bolt. Tighten: Tighten the bolts to 25 N.m (18 lb in).

1. Remove the front air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bumper-system-fascia) .
2. Disconnect the coolant heater cord electrical connector (3) from the coolant heater electrical connector (2).
3. Remove the coolant heater bolt.
4. Remove the coolant heater.

1. Position the coolant heater to the engine block.
2. Install the coolant heater bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
3. Connect the coolant heater cord electrical connector (3) to the coolant heater electrical connector (2).
4. Remove the front air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/dts/i-2005-2011/remont/exterior-body-panels/#bumper-system-fascia) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
2. Disconnect the coolant heater cord electrical connector (2) from the coolant heater electrical connector (1).
3. Remove the coolant heater bolt.
4. Remove the coolant heater.

1. Position the coolant heater to the engine block.
2. Install the coolant heater bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
3. Connect the coolant heater cord electrical connector (2) to the coolant heater electrical connector (1).
4. Lower the vehicle.

1. Remove the surge tank inlet hose/pipe. Refer to «Radiator Surge Tank Inlet Hose/Pipe Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Disconnect the coolant heater cord electrical connector (2) from the right coolant heater electrical connector (1).
3. Disconnect the coolant heater cord electrical connector (3) from the left coolant heater electrical connector (2).
4. Cut the coolant heater cord strap (4) at the engine harness.
5. Remove the coolant heater cord clip (1) from the lift hook bracket.
6. Remove the coolant heater cord clips from the fuel rail studs.
7. Cut the coolant heater cord strap at the engine harness.

1. Install the coolant heater cord clips to the fuel rail studs.
2. Install a NEW strap attaching the coolant heater cord to the engine harness.
3. Install the coolant heater cord clip (1) to the lift hook bracket.
4. Install a NEW strap attaching the coolant heater cord to the engine harness.
5. Connect the coolant heater cord electrical connector (3) to the left coolant heater electrical connector (2).
6. Connect the coolant heater cord electrical connector (2) to the right coolant heater electrical connector (1).
7. Install the surge tank inlet hose/pipe. Refer to «Radiator Surge Tank Inlet Hose/Pipe Replacement»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

Scheme 7

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) or powertrain control module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood fuse block.

During low speed operation, the ECM or PCM supplies the ground path for the R1 Cool/Fan 1 Relay through the low speed cooling fan relay control circuit. This energizes the R1 Cool/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 cooling fan. The ground path for the left cooling fan is through the R7 Cool/Fan 2 Relay and the right cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation, the ECM or PCM supplies the ground path for the R1 Cool/Fan Relay through the low speed cooling fan relay control circuit. After a 3-second delay, the ECM or PCM supplies a ground path for the R2 Cool/Fan Relay and the R 7 Cool/Fan 2 Relay through the high speed cooling fan relay control circuit. This energizes the R7 Cool/Fan 2 Relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time, the R2 Cool/Fan Relay coil is energized closing the relay contacts, and provides battery positive voltage from the high fan fuse on the cooling fan motor supply voltage circuit, to the right cooling fan. During high speed fan operation, both engine cooling fans have their own ground path. The result is a parallel circuit with both fans running at high speed.

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

Cooling Fan Control - Two Fan System

The engine cooling fan system consists of 2 puller type 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 and fan relays receive battery positive voltage from the underhood fuse block. The ground path is provided at G104.

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

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

The ECM commands the low speed cooling fans ON under the following conditions

1. Engine coolant temperature exceeds approximately 94.5°C (202°F).
2. A/C refrigerant pressure exceeds 1447 kPa (210 psi).
3. After the vehicle is shut OFF, if the engine coolant temperature at key-off is greater than 101°C (214°F), the low speed fans will run for a minimum of 60 seconds. After 60 seconds, if the coolant temperature drops below 101°C (214°F), the fans will shut OFF. The fans will automatically shut OFF after 3 minutes, regardless of coolant temperature.

The ECM commands the high speed fans ON under the following conditions

1. Engine coolant temperature exceeds approximately 104.25°C (220°F).
2. A/C refrigerant pressure exceeds approximately 1824 kPa (265 psi).
3. When certain DTCs set

At idle and very low vehicle speeds the cooling fans are only allowed to increase in speed, if required. This ensures idle stability by preventing the fans from cycling between high and low speed.

Engine Coolant

Engine coolant is the key element of the heating system. The engine thermostat controls the normal engine operating coolant temperature. Coolant pumped out of the engine block enters the heater core through the inlet heater hose. The air flowing through the HVAC module absorbs the heat of the coolant flowing through the heater core. The coolant then exits the heater core through the heater outlet hose. To prevent the coolant from boiling after the engine is turned OFF an after-boil/heater coolant pump is used.

The HVAC control module will command the after-boil/heater coolant pump ON, when the engine is OFF, under the following conditions

1. The engine is OFF.
2. The engine coolant temperature is above 101°C (214°F).

The above coolant flow circuits are designed to show the coolant flow related to the coolant by-pass valve positions only. The thermostat function and thermostat coolant flow paths are not shown.

Coolant Warning Messages

The radio will display the following messages if the following conditions exist in the cooling system.

1. Engine hot-A/C OFF will be displayed if coolant temperature is above 117°C (243°F). For imports 115°C (239°F).
2. Engine coolant hot-Idle engine will be displayed if coolant temperature is above 118°C (245°F).
3. Engine overheated-Stop engine will be displayed if coolant temperature is above 123°C (253°F).

Coolant Level Control

The engine cooling system contains an engine coolant level switch to alert the driver in the event of a low coolant level. When the engine coolant level in the surge tank falls below a certain level, the coolant level switch opens. When the HVAC control module detects an open, or a high voltage level on the coolant level indicator control circuit for at least 10 seconds, it will send a class 2 message to the radio requesting display of the low coolant level message. There is approximately a 10 second delay before the HVAC control module sends a class 2 message, to prevent the message from being displayed due to coolant sloshing in the surge tank.

Coolant Heater

The optional engine coolant heater (RPO K05) operates using 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 maintains an efficient engine operating temperature during all engine speeds and operating conditions. The cooling system removes approximately one-third of the heat produced by the burning of the air-fuel mixture. When the engine is cold, the system cools slowly or not at all, allowing the engine to warm quickly.

Cooling Cycle

The thermostat is located between the radiator outlet and the water pump inlet. At normal operating temperature, coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. In cold conditions, the thermostat bypasses the radiator, and the pump draws coolant directly from the engine outlet.

Coolant is then pumped through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders and 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, absorbing additional heat.

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

From the cylinder heads, the coolant is then forced to the engine outlet. Coolant leaves the engine through 4 different routes

1. Through the engine outlet fitting to the radiator. This path is blocked at cold conditions by the thermostat at the engine inlet fitting.
2. Through the radiator bypass
3. To the heater core for passenger compartment heat and defrost
4. Through the vent hose to the surge tank, providing continuous de-aeration of the cooling system

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 clean drinkable 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 crossflow tube and fin design. This is a brazed tube with convoluted louvered fin design. Separate tubes and fins are stacked together with a manifold at each end. The entire core assembly is then brazed, forming a homogeneous unified structure. The fins allow for efficient heat transfer from the coolant to the atmosphere. The inlet and outlet tanks are molded with a high temperature, glass reinforced nylon plastic. The tank and gasket is supplied as an assembly with silicone gasket attached to the tank. 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 which is located in the bottom of the passenger side tank. The drain cock includes the drain cock and drain cock seal.

The radiator removes heat from the coolant passing through the radiator. The fins on the core absorb heat from the coolant passing through the tubes. Air passing between the fins absorbs heat and cools the coolant.

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. Coolant without bubbles absorbs heat much better than coolant with bubbles.

Pressure Cap

The pressure cap seals and pressurizes the cooling system. The cap contains a blow off or pressure valve and a vacuum or atmospheric valve. The pressure valve is held against the valve seat by a spring which protects the radiator by relieving pressure exceeding 15 psi. The vacuum valve is held against the valve seat by a spring which permits opening of the valve to relieve vacuum created in the cooling system during cooling. The vacuum, if not relieved, could cause the radiator hoses to collapse.

The pressure cap allows pressure in the cooling system to build up. As the pressure builds, the boiling point of the coolant rises as well. Therefore, the coolant can be safely run at a temperature higher than the boiling point of the coolant at atmospheric pressure. The hotter the coolant is, the faster the heat moves from the radiator to the cooler, passing air. However, if the pressure exceeds the strength of the spring, the pressure valve rises so that the excess pressure can escape. When 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 cooling system. This equalizes the pressure in the cooling system with atmospheric pressure, thus preventing the radiator hoses from collapsing.

Surge Tank

The surge tank is a plastic tank with a mounted pressure cap. 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, because coolant without bubbles absorbs heat much better than coolant with bubbles.

Air Baffles & Seals

The cooling system uses deflectors, air baffles, and air seals to increase system cooling. Deflectors are installed under the vehicle which redirect airflow beneath the vehicle to flow through the radiator and increase cooling. Air baffles are also used to direct airflow into the radiator and increase cooling. Air seals prevent air from bypassing the radiator and A/C condenser. Air seals also prevent recirculation of the 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 and an impeller. The impeller is a flat plate mounted on the pump shaft with a series of flat or curved blades or vanes. When the impeller rotates, the coolant between the vanes is thrown outward by centrifugal force. The impeller shaft is supported by one or more sealed bearings. 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 drive belt.

Thermostat

The thermostat is a coolant flow control component. Its purpose is to regulate the operating temperature of the engine. It utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a piston. When the element is heated, it expands and exerts pressure against a rubber diaphragm. 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 quickly. After the coolant temperature reaches 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, even 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.

Engine Oil Heat Exchanger

The engine oil heat exchanger is mounted to the top of the engine block, under the intake manifold flange. Oil is pumped through the oil cooler inlet pipe to the heat exchanger, back through the oil cooler outlet pipe, and then to the oil passages in the engine for lubrication. The exchanger provides the following 2 functions

1. Engine coolant warms up faster than the engine oil. During cold operation, the coolant warms the oil and provides better flow during cold engine operation.
2. After the engine reaches normal operating temperature, the engine oil temperature will exceed the engine coolant temperature. The coolant flowing through the engine oil cooler will absorb heat from the engine oil. Cooling the engine oil extends oil life and helps reduce internal engine wear.

Transmission Oil Cooler - V09

Note. The transmission oil cooler system uses quick connect fittings throughout the system. Use a special tool to disconnect these quick connect fittings. Removing the transmission oil cooler lines without this tool will result in damage to the radiator, the transmission, and the transmission oil cooler caused by mixing the transmission oil and coolant or due to transmission oil loss.

The transmission oil cooler (TOC) is an oil-to-water heat exchanger located in the radiator end tank and is non-serviceable. The transmission oil temperature is regulated by the temperature of the coolant leaving the radiator. The oil out of the transmission is plumbed through the TOC lines to the radiator end tank cooler then directed back to the transmission.

Transmission Oil Cooler - V03/V92

Note. The transmission oil cooler system uses quick connect fittings throughout the system. Use a special tool to disconnect these quick connect fittings. Removing the transmission oil cooler lines without this tool will result in damage to the radiator, the transmission, and the transmission oil cooler caused by mixing the transmission oil and coolant or due to transmission oil loss.

The transmission oil cooler (TOC) is an oil-to-air heat exchanger located between the radiator and the A/C condenser. The transmission oil temperature is regulated by the airflow passing over this heat exchanger. The oil out of the transmission is plumbed through the TOC lines to the cooler then directed back to the transmission. This cooler helps provided additional cooling for performance driving conditions.

Transmission Oil Cooler Lines

Note. The transmission oil cooler system uses quick connect fittings throughout the system. Use a special tool to disconnect these quick connect fittings. Removing the transmission oil cooler lines without this tool will result in damage to the radiator, the transmission, and the transmission oil cooler caused by mixing the transmission oil and coolant or due to transmission oil loss.

The transmission oil cooler (TOC) lines use quick connect fittings that must be removed using a special tool. The oil out of the transmission is pumped at a high pressure through the TOC lines to the heat exchanger and then directed back to the transmission.

Power Steering Oil Cooler

Some vehicles are equipped with a power steering oil cooler located either between the radiator and condenser (Heavy Duty) or in front of the engine. This cooler transfers heat from the power steering system to the air passing through the condenser and radiator. The cooler uses constant tension clamps on the hose connections to the cooler.

Special Tools

Illustration Tool Number / Description DT-47731 1/2 Inch Quick Connect Release Tool GE 47716 Vac N Fill Coolant Refill Tool J 24460-01 Cooling System Pressure Tester J 24731 Tempilstick J 26568 Coolant and Battery Fluid Tester J 38185 Hose Clamp Pliers J 38823 Water Pump Pulley Installer J 38825 Power Steering and Water Pump Pulley Remover J 41623-B Cooler Quick Connect Tool J 42401 Radiator Cap and Surge Tank Test Adapter J 43244 Relay Puller Pliers

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Engine Control Module Description
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Probing Electrical Connectors
• Powertrain Diagnostic Trouble Code (DTC) Type Definitions
• Control Module References
• Instrument Cluster Description and Operation
• Indicator/Warning Message Description and Operation
• Audible Warnings Description and Operation
• Coolant in Combustion Chamber
• Diagnostic Repair Verification
• Checking Aftermarket Accessories
• Heater Core Replacement
• Engine Coolant/Water in Transmission
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Coolant in Engine Oil
• Lower Engine Noise, Regardless of Engine Speed
• Cylinder Leakage Test
• Air Cleaner Assembly Replacement
• Lifting and Jacking the Vehicle
• Front Air Deflector Replacement
• Approximate Fluid Capacities
• Fastener Notice
• Fuel Injector Sight Shield Replacement
• Battery Negative Cable Disconnection and Connection
• Front End Upper Tie Bar Replacement
• Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection
• DTC P0480 or P0481
• Symptoms - Engine Cooling
• Engine Overheating
• Loss of Coolant
• Engine Fails To Reach Normal Operating Temperature
• Pressure Cap Testing
• Cooling System Leak Testing
• Cooling System Draining and Filling (Vac-N-Fill)
• Cooling System Draining and Filling (Static Fill)
• Flushing
• Special Tools
• Fastener Tightening Specifications
• Fan Shroud Replacement