Engine Fails To Reach Normal Operating Temperature. Cadillac CTS 2004

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2004 🢒 CTS 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Engine Fails To Reach Normal Operating Temperature

Engine Fails To Reach Normal Operating Temperature LA3, LY9

The engine may fail to reach normal operating temperature due to an intermittent operation of one of the following components:

•	The coolant bypass valve

•	The thermostat

For electrical inspection of the coolant bypass solenoid, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step	Action	Yes	No
DEFINITION: Normal coolant temperature readings will be expected to vary from 92°C (198°F) and 107°C (225°F).
1	Did you perform the engine cooling diagnostic system check?	Go to Step 2	Go to Diagnostic System Check - Engine Cooling
2	Verify that the engine fails to reach normal operating temperature. Is the engine failing to reach normal operating temperature?	Go to Step 3	Go to Diagnostic Aids
3	Inspect the surge tank for low coolant. Is there a loss of coolant?	Go to Loss of Coolant	Go to Step 4
4	Inspect for an inoperative coolant bypass valve. Refer to Coolant Bypass Valve Inoperative . Does the engine still fail to reach normal operating temperature?	Go to Step 5	Go to Step 7
5	Inspect the thermostat for proper operation. Refer to Thermostat Diagnosis . Does the thermostat operate properly?	Go to Step 7	Go to Step 6
6	Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Did you complete the repair?	Go to Step 7	--
7	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2

Step	Action	Yes	No
1	Ensure that the cooling system is full. Allow the engine to cool. Start the engine. Turn the air conditioning system off. Inspect the engine cooling fan(s). Is the electric cooling fan on?	Go to Step 2	Go to Step 3
2	Diagnose and repair the cooling fan system. Refer to Cooling Fan Always On and Cooling Fan Always On - Auxiliary . Verify the customer complaint. Does the engine still fail to reach normal operating temperature?	Go to Step 3	System OK
3	Install the Scan Tool to the DLC. Compare the Scan Tool coolant temperature reading to the I/P cluster coolant temperature. Is the I/P cluster coolant temperature close to the reading on the Scan Tool?	Go to Step 5	Go to Step 4
4	Diagnose and repair the coolant temperature gage system. Verify the customer complaint. Does the engine still fail to reach normal operating temperature?	Go to Step 5	System OK
5	Inspect the thermostat for proper operation. Refer to Thermostat Diagnosis . Is the thermostat operating properly?	Go to Step 1	Go to Step 6
6	Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Verify the customer complaint. Does the engine still fail to reach normal operating temperature?	Go to Step 1	System OK