Circuit/System Verification

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

Engine running
Verify the E18 Rear Defogger Grid turns ON and OFF when commanding the Rear Defogger On and Off with a scan tool
- If the E18 Rear Defogger Grid does not turn ON or OFF
  Refer to Rear Window Defogger Malfunction .
- If the E18 Rear Defogger Grid turns ON and OFF
Verify the E17D Outside Rearview Mirror Glass-Driver and the E17P Outside Rearview Mirror Glass-Passenger become warm when commanding the Rear Defogger On with a scan tool.
- If the E17D Outside Rearview Mirror Glass-Driver or E17P Outside Rearview Mirror Glass-Passenger do not become warm
  Refer to Circuit/System Testing - Single Outside Mirror Defogger Inoperative.
- If both E17D Outside Rearview Mirror Glass-Driver and E17P Outside Rearview Mirror Glass-Passenger never become warm or are always warm
  Refer to Circuit/System Testing - Both Outside Mirrors Defogger Malfunction.
- If both the E17D Outside Rearview Mirror Glass-Driver and the E17P Outside Rearview Mirror Glass-Passenger become warm
All OK.