ACI 318-14 (Table 11.5.4.6)

Where M_u/V_u ratio used in equation (e) was calculated at the critical section above the base of the wall (see Figure 1).

ACI 318-14 (11.5.4.7)

The factored moment at the ultimate section is equals to:

Where ϕ = 0.75 for shear

ACI 318-14 (Table 21.2.1)

Thus, it is not required to calculate the additional shear strength provided by the horizontal reinforcement (V_s)

Since 0.5ϕV_c is less than V_u, ρ_l shall be at least the greater of Equation 11.6.2 in the Code and 0.0025 but need not to exceed ρ_t required by Equation 11.5.4.8. and ρ_t shall be at least 0.0025. 

(Those requirements were checked in step 1).

ACI 318-14 (11.6.2)