  Recently, a covariant spherically symmetric model of a black hole within the
framework of loop quantum gravity (LQG), characterized by a quantum parameter
$r_0$ or $\lambda$, has been proposed. To derive constraints on the
LQG-corrected parameter, we explore observational constraints imposed on $r_0$
and $\lambda$ through investigations of the light deflection, the Shapiro time
delay, the precession of perihelia, and the geodetic precession test. Among
these constraints, the tightest one arises from the Shapiro time delay measured
by the Cassini mission, yielding an upper constraint of approximately
$10^{-5}$.
