Check for continuity between heater control unit connector B (12P) No. 10 terminal and the in-car temperature sensor 2P connector No. 2 terminal.
Is there continuity?
YES
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Check for loose wires or poor connections at heater control unit connectors A (28P), B (12P), and at the in-car temperature sensor 2P connector. If the connections are good, substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original
heater control unit
.■
NO
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Repair open in the wire between the heater control unit and the in-car temperature sensor.■