Canon EOS-1D X Mark III Advanced User's Manual page 817

2.
Check the details as needed.
Note
The camera status log screen lists the five most recent error
records. If more than five records are logged, the oldest record is
deleted automatically.
Shutter-release cycles are indicated in units of 1,000.
3.
Check the log as needed.
On the screen in step 2, press the <
"Err **" indicates error information (
> button.
).
817