Circuit/System Verification
- Ignition ON.
- Verify the vehicle lamps listed below turn ON and OFF when commanding the appropriate control function ON and OFF:
- Park lamps turn ON and OFF when commanding the Park Lamps ON and OFF with the headlamp switch.
- Backup lamps turn ON and OFF when commanding the Backup Lamps ON and OFF with a scan tool.
- Left and right brake lamps turn ON and OFF when commanding the Brake Lamps ON and OFF with the brake pedal.
- Left and right turn signal lamps turn ON and OFF when commanding the left and right turn signal lamps ON and OFF with the turn signal/multifunction switch.
- If the lamps on the vehicle do not turn ON and OFF
Refer to the appropriate malfunction procedure listed below:
- If the park lamps do not turn ON and OFF, refer to Park, License, and/or Tail Lamps Malfunction .
- If the backup lamps do not turn ON and OFF, refer to Backup Lamps Malfunction .
- If the left and right brake lamps do not turn ON and OFF, refer to Stop Lamps Malfunction .
- If the left and right turn signal lamps do not turn ON and OFF, refer to Turn Signal Lamps and/or Indicators Malfunction .
- Go to next step: If the lamps on the vehicle turn ON and OFF
- Connect a test lamp between the appropriate trailer lamp fuse listed below and ground:
- Trailer park lamps = Fuse F23UA
- Trailer backup lamps = Fuse F11UA
- Trailer left stop/turn signal lamps = Fuse F27UA
- Trailer right stop/turn signal lamps = Fuse F24UA
- Verify the test lamp turns ON and OFF when commanding the appropriate control function listed below ON and OFF:
- Trailer park lamps = Park lamp switch ON and OFF
- Trailer backup lamps = Backup Lamps scan tool control function ON and OFF
- Trailer left stop/turn signal lamps = Left turn signal switch ON and OFF
- Trailer right stop/turn signal lamps = Right turn signal switch ON and OFF
- If the test lamp does not turn ON and OFF
Refer to Circuit/System Testing - Relay Control Malfunction
- Go to next step: If the test lamp turns ON and OFF
- Connect a test lamp between the appropriate trailer lamp terminal listed below and ground:
- Trailer park lamps
- Trailer backup lamps
- Left trailer turn signal/stop lamp
- Right trailer turn signal/stop lamp
- Verify the test lamp turns ON and OFF when commanding the appropriate lamp ON and OFF with the control function listed below:
- Trailer park lamps = Park lamp switch ON and OFF
- Trailer backup lamps = Backup Lamps scan tool control function ON and OFF
- Left trailer turn signal/stop lamp = Left turn signal switch ON
- Right trailer turn signal/stop lamp = Right turn signal switch ON
- If the test lamp does not turn ON and OFF
Refer to Circuit/System Testing - Trailer Lighting Malfunction
- Go to next step: If the test lamp turns ON and OFF
- All OK.
NOTE:
Refer to the cover of the X88 Trailer Connector to identify the appropriate terminal to test at.