Autel Autolink AL539B Manual page 55

RED LED – Indicates there is a problem with one or more of
3)
the vehicle's system. A vehicle displaying a red LED is
definitely not ready for an Emissions Test. The red LED is also
an indication that there are DTCs present. The MIL lamp on the
vehicle's instrument panel will light steady. The problem that is
causing the red LED to light must be repaired before an
Emissions Test can be performed. It is also suggested that the
vehicle be inspected/repaired before driving the vehicle further.
If the RED LED was obtained, there is a definite problem
present in the system(s). In these cases, you have the following
options:

Repair the vehicle yourself. If you are going to perform the
repairs yourself, proceed by reading the vehicle service
manual
recommendations.

Take the vehicle to a professional to have it serviced. The
problem(s) causing the red LED to light must be repaired
before the vehicle is ready for an Emissions Test.
Audio Tone Interpretation
The audio tone is configured according to the I/M Readiness Status.
This function is invaluable when performing diagnostics and driving
at the same time, or working in bright areas where LED illumination
alone is not sufficient.
Different audio tone with different LED light indicates different I/M
Readiness Status.
LED Light
Green LED
Yellow LED
Red LED
and following
Audio Tone
Two long beeps
short, long, short beep
Four short beeps
53
all its procedures
Beep Interval
5 seconds
5 seconds
5 seconds
and