Circuit/System Verification

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2015 GMC Yukon XL, 2015 GMC Yukon, 2015 Chevrolet Tahoe, 2015 Chevrolet Suburban, and 2015 Cadillac Escalade ESV. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON.
Verify the scan tool can communicate with the B218L Side Object Sensor Module - Left.
- If the scan tool cannot communicate with the B218R Side Object Sensor Module - Left
  Refer to Circuit/System Testing - Left Side Object Sensor Malfunction.
- If the scan tool can communicate with the B218L Side Object Sensor Module - Left
Verify DTC U18A6 is not set.
- If DTC U18A6 is set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If DTC U18A6 is not set
Ignition OFF, ignition ON.
Verify that both side blind zone alert system indicators located in the outside rearview mirrors briefly turn ON and then turn OFF during the system self test.
- If both side blind zone alert indicators do not briefly turn ON and OFF
1. Verify the system is enabled
  - If disabled, refer to Diagnostic Aids for cause of disable.
  - If enabled, refer to Circuit/System Testing - Side Object Indicator Malfunction.
- If only one indicator does not briefly illuminate during the self test
  Refer to Circuit/System Testing - Side Object Indicator Malfunction.
- If both side blind zone alert indicators briefly turn ON and OFF
Verify that both side blind spot indicators turn ON and OFF when commanding the Object Detection Alert Indicators On and Off with a scan tool.
- If both indicators do not turn ON and OFF
  Replace the B218R Side Object Sensor Module - Right.
- If one indicator does not turn ON and OFF
  Refer to Circuit/System Testing - Side Object Indicator Malfunction.
- If both indicators turn ON and OFF
All OK.