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Home >> GMC >> 2018 >> Acadia Denali, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 218 (Transfer Case - BW 4474) >> Diagnostic Information and Procedures >> All-Wheel Drive Off Indicator Always On >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.
    IMPORTANT:

    The instrument panel will display AWD OFF once 135°C (275°F) has been met or exceeded. The transfer case temperature sensor DTC will not set until 154°C (309°F) has been met.

  1. Check for any transfer case DTCs and diagnose as necessary.
  2. Check for any U codes which may indicate the reason why wheel speed or vehicle speeds are missing and diagnose as necessary using the U code diagnostics.
  3. Using a scan tool under transfer case data list look at the transfer case oil temperature. If the temperature is at or above 135°C (275°F) determine that the vehicle is not being used beyond its design intent. If this is not the case then the overheat condition may be due to excessively slipping clutches. Allow the transfer case to cool and retest. If the condition persists then disassemble the transfer case and repair as necessary. If an overheating issue is not present go to the next step.
  4. Check the ECM and EBCM for DTCs as these modules will likely have set DTCs due to faulty wheel or vehicle speeds. Follow the proper diagnostics and repair as necessary.
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