Heating and A/C

The blower fan runs slower than expected in cold weather (when in AUTO mode)

Probable cause: Engine coolant temperature (ECT) circuit malfunction

Troubleshoot the ECT sensor circuit:

ECT sensor 2 circuit low voltage P2184

ECT sensor 2 circuit high voltage P2185

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HVAC DTCs How to Troubleshoot the Heating and A/C Systems

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Powertrain DTCs Initial Inspection and Diagnostic Overview

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Blower motor operation