diff --git a/test/extensions/fmi.jl b/test/extensions/fmi.jl
index 7e5e01f76a..2fc385934f 100644
--- a/test/extensions/fmi.jl
+++ b/test/extensions/fmi.jl
@@ -3,34 +3,73 @@ using ModelingToolkit: t_nounits as t, D_nounits as D
 import ModelingToolkit as MTK
 
 @testset "Standalone pendulum model" begin
+    fmu = loadFMU("SpringPendulum1D", "Dymola", "2022x"; type = :ME)
+    truesol = FMI.simulate(
+        fmu, (0.0, 8.0); saveat = 0.0:0.1:8.0, recordValues = ["mass.s", "mass.v"])
+
     @testset "v2, ME" begin
         fmu = loadFMU("SpringPendulum1D", "Dymola", "2022x"; type = :ME)
-        @mtkbuild sys = MTK.FMIComponent(Val(2), Val(:ME); fmu)
+        @mtkbuild sys = MTK.FMIComponent(Val(2); fmu, type = :ME)
         prob = ODEProblem{true, SciMLBase.FullSpecialize}(
             sys, [sys.mass__s => 0.5, sys.mass__v => 0.0], (0.0, 8.0))
         sol = solve(prob, Tsit5(); reltol = 1e-8, abstol = 1e-8)
         @test SciMLBase.successful_retcode(sol)
 
-        truesol = FMI.simulate(fmu, (0.0, 8.0); saveat = 0.0:0.1:8.0)
-        @test sol(0.0:0.1:8.0).u≈truesol.states.u atol=1e-4
+        @test sol(0.0:0.1:8.0;
+            idxs = [sys.mass__s, sys.mass__v]).u≈collect.(truesol.values.saveval) atol=1e-4
         # repeated solve works
         @test_nowarn solve(prob, Tsit5())
     end
+    @testset "v2, CS" begin
+        fmu = loadFMU("SpringPendulum1D", "Dymola", "2022x"; type = :CS)
+        @named inner = MTK.FMIComponent(
+            Val(2); fmu, communication_step_size = 0.001, type = :CS)
+        @variables x(t) = 1.0
+        @mtkbuild sys = ODESystem([D(x) ~ x], t; systems = [inner])
+
+        prob = ODEProblem{true, SciMLBase.FullSpecialize}(
+            sys, [sys.inner.mass__s => 0.5, sys.inner.mass__v => 0.0], (0.0, 8.0))
+        sol = solve(prob, Tsit5(); reltol = 1e-8, abstol = 1e-8)
+        @test SciMLBase.successful_retcode(sol)
+
+        @test sol(0.0:0.1:8.0;
+            idxs = [sys.inner.mass__s, sys.inner.mass__v]).u≈collect.(truesol.values.saveval) rtol=1e-2
+    end
 end
 
 @testset "IO Model" begin
-    fmu = loadFMU("./fmus/SimpleAdder.fmu"; type = :ME)
-    @named adder = MTK.FMIComponent(Val(2), Val(:ME); fmu)
-    @variables a(t) b(t) c(t) [guess = 1.0]
-    @mtkbuild sys = ODESystem(
-        [adder.a ~ a, adder.b ~ b, D(a) ~ t,
-            D(b) ~ adder.out + adder.c, c^2 ~ adder.out + adder.value],
-        t;
-        systems = [adder])
-
-    # c will be solved for by initialization
-    # this tests that initialization also works with FMUs
-    prob = ODEProblem(sys, [sys.adder.c => 1.0, sys.a => 1.0, sys.b => 1.0], (0.0, 1.0))
-    sol = solve(prob, Rodas5P(autodiff = false))
-    @test SciMLBase.successful_retcode(sol)
+    @testset "v2, ME" begin
+        fmu = loadFMU("../../omc-fmus/SimpleAdder.fmu"; type = :ME)
+        @named adder = MTK.FMIComponent(Val(2); fmu, type = :ME)
+        @variables a(t) b(t) c(t) [guess = 1.0]
+        @mtkbuild sys = ODESystem(
+            [adder.a ~ a, adder.b ~ b, D(a) ~ t,
+                D(b) ~ adder.out + adder.c, c^2 ~ adder.out + adder.value],
+            t;
+            systems = [adder])
+
+        # c will be solved for by initialization
+        # this tests that initialization also works with FMUs
+        prob = ODEProblem(sys, [sys.adder.c => 1.0, sys.a => 1.0, sys.b => 1.0], (0.0, 1.0))
+        sol = solve(prob, Rodas5P(autodiff = false))
+        @test SciMLBase.successful_retcode(sol)
+    end
+    @testset "v2, CS" begin
+        fmu = loadFMU("../../omc-fmus/SimpleAdder.fmu"; type = :CS)
+        @named adder = MTK.FMIComponent(
+            Val(2); fmu, type = :CS, communication_step_size = 0.001)
+        @variables a(t) b(t) c(t) [guess = 1.0]
+        @mtkbuild sys = ODESystem(
+            [adder.a ~ a, adder.b ~ b, D(a) ~ t,
+                D(b) ~ adder.out + adder.c, c^2 ~ adder.out + adder.value],
+            t;
+            systems = [adder])
+
+        # c will be solved for by initialization
+        # this tests that initialization also works with FMUs
+        prob = ODEProblem(sys, [sys.adder.c => 1.0, sys.a => 1.0, sys.b => 1.0],
+            (0.0, 1.0); use_scc = false)
+        sol = solve(prob, Rodas5P(autodiff = false))
+        @test SciMLBase.successful_retcode(sol)
+    end
 end