Info starts a little after the task light info.
They are part of the 'cargo light' circuitry / logic.
Auxiliary Cargo Mirror Lamps
If equipped, cargo mirror lamps face rearward to provide more light on the sides of the vehicle, if needed.
See Exterior Cargo Lamps pg 144.
pg 144
Exterior Cargo Lamps
The cargo lamps provide more light in the cargo area or on the sides of the vehicle,
if needed. The lamps inside the pickup box, in the tailgate handle, for the hitch, and/or the cargo mirror lamps also turn on, if equipped.
If the vehicle is in P (Park), R (Reverse), or N (Neutral)
the Cargo Lamp Switch causes the lights to cycle through the following states for each button press:
- Initial Press:
- CHMSL/Cargo Bed Lights - On
- Cargo Mirror Lights - On
- Cargo Switch Indicator (if equipped) - On
- Next Press: (if with in 5 seconds of the previous button press):
- CHMSL/Cargo Bed Lights - On
- Cargo Mirror Lights - Off
- Cargo Switch Indicator (if equipped) - On
- Next Press:
- CHMSL/Cargo Bed Lights - Off
- Cargo Mirror Lights - Off
- Cargo Switch Indicator (if equipped) - Off
So, there are 3 possible modes the Cargo Lights/Mirror backup lights can operate, (based on the number of button presses)
All off
Mirror lights off and CHMSL/Bed light on (and indicator in switch on)
All on (and indicator in switch on)
------------------------------------------------------------------------------------------------------------------------------
Cutting through the details, pushing the cargo light button once should get the truck out of the 'all on mode' and the mirror reverse LED's should be off.