Symptoms - Engine Cooling
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Symptoms - Engine Cooling
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Important Preliminary Inspections Before Starting
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Before using the Symptom diagnosis, perform the following:
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Ensure that the engine control module (ECM) and indicator lamp are operating correctly.
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Ensure that there are no diagnostic trouble codes (DTCs) that are stored.
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Scan tool data is within a normal operating range.
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Verify the customer concern.
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Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.
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Locate the correct symptom. Perform the tests and inspections associated with the symptom.
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Review the entire cooling system operation in order to familiarize yourself with the system functions. Refer to
Cooling Fan Description and Operation (LF1)
Cooling Fan Description and Operation (LAU)
and
Cooling System Description and Operation
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Visual/Physical Inspection
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Warning
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Use the connector test adapter kit EL-35616-F for any test that requires probing the following items:
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The control module harness connectors
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The electrical center fuse/relay cavities
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The component terminals
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The component harness connector
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Using this kit will prevent damage caused by the improper probing of connector terminals.
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Several of the symptom procedures call for a careful visual and physical inspection. This can lead to correcting a condition without further tests and can save time. This inspection should include the following areas:
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Ensure that the control module grounds are clean, tight, and correctly located.
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Inspect cooling system hoses and pipes for splits, kinks, and proper connections. Inspect thoroughly for any type of a leak or a restriction.
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Inspect for a dirty or restricted radiator and HVAC condenser.
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Inspect for aftermarket devices which could affect the operation of the Cooling System.
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Inspect for easily accessible or visible system components for obvious damage or conditions which may cause the symptom.
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Inspect the surge tank reservoir for the proper coolant level.
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Identifying Intermittent Conditions
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Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movement of a component. Refer to the following for a list to help isolate an intermittent condition:
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Moisture and water intrusion in connectors, terminals, and components
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High circuit or component resistance. High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
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Harness' that are routed too tight, or chaffed circuits
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High or low ambient temperature
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High or low engine coolant temperatures
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High underhood temperatures
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Heat build up in component or circuit due to circuit resistance, poor terminal contact, or high electrical load
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High or low system voltage
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High vehicle load conditions
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Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
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Incorrect installation of non-factory, aftermarket, and after factory add on accessories
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If an intermittent is detected, refer to
Testing for Intermittent Conditions and Poor Connections
for specific strategies in diagnosing intermittent conditions.
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
