Diagnostic procedure
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STEP
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INSPECTION
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ACTION
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1
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INSPECT COOLANT TEMPERATURE
• Is coolant sufficiently warmed up?
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Yes
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Go to the next step.
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No
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Warm engine up, then go to Step 8.
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2
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INSPECT A/C UNIT AIR MIX SYSTEM
• Inspect A/C unit air mix links, air mix cranks, air mix rods, air mix actuator or wire clamp.
• Are above items okay?
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Yes
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Go to the next step.
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No
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Apply grease or install links, cranks, and rods securely in their proper positions, repair or replace air mix actuator or wire clamp, then go to Step 8.
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3
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VERIFY THAT AIR MIX WIRE FROM A/C UNIT IS POSITIONED SECURELY AND CORRECTLY (IF AVAILABLE)
• Is air mix wire securely installed in the correct position in relation to A/C unit air mix links?
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Yes
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Go to the next step.
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No
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Adjust air mix wire or install securely in correct position, then go to Step 8.
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4
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INSPECT CLIMATE CONTROL UNIT
• Inspect climate control unit. (See CLIMATE CONTROL UNIT INSPECTION.)
• Is climate control unit okay?
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Yes
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Go to the next step.
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No
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Repair or replace climate control unit, then go to Step 8.
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5
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INSPECT A/C UNIT
• Is there any foreign material or obstruction in A/C unit air mix doors?
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Yes
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Remove obstruction, then go to Step 8.
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No
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Go to the next step.
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6
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INSPECT A/C UNIT AIR MIX DOORS
• Is A/C unit air mix door securely and properly installed?
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Yes
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Inspect air mix door for cracks or damage, then go to the next step.
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No
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Install air mix door securely in proper position, then go to the next step.
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7
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INSPECT HEATER LINES
• Inspect heater lines.
• Are above items okay?
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Yes
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Operation is okay. Recheck malfunction symptoms.
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No
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If heater piping connections is loosed, tighten connections with specified torque.
Repair or replace heater piping, then go to the next step.
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8
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VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER REPAIR
• Does unit operate in every temperature setting?
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Yes
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Troubleshooting completed.
Explain repairs to customer.
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No
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Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.
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