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Home >> Hyundai >> 1994 >> Excel Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Diagnostic Tests >> Code 21 - Coolant Temperature Sensor Failure >> System Inspection
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System Inspection

Inspect condition of connector. Clean and repair as needed. Faulty Coolant Temperature Sensor (CTS) can cause incorrect idle RPM during cold start-up condition and rich air/fuel mixture.