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Circuit/System Verification

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
  1. Engine Running.
  2. Verify the scan tool ECM A/C Request Signal parameter is Yes in only the following mode switch positions:
    • MAX A/C
    • A/C
    • Bi- Level
    • Defrost
    • Blend
    • If the parameter is not Yes in only the specified mode switch positions 

      Refer to Circuit/System Testing - A/C Request Malfunction.

    • Go to next step: If the parameter is Yes in only the specified mode switch positions 
  3. Verify the A/C compressor clutch engages and disengages when commanding the A/C Relay On and Off with a scan tool.
    • If the A/C compressor clutch does not engage and disengage 

      Refer to Circuit/System Testing - A/C Compressor Malfunction.

    • Go to next step: If the A/C compressor clutch does engage and disengage 
  4. All OK.
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