diff --git a/tc/obsw_tc_service5_17.py b/tc/obsw_tc_service5_17.py
index bd8f9a896c7fbc4a437f9a54c63e936b7438cd13..d1e5748e2e1c38282147c6f00778c399187108cf 100644
--- a/tc/obsw_tc_service5_17.py
+++ b/tc/obsw_tc_service5_17.py
@@ -9,6 +9,7 @@
 
 from tc.obsw_pus_tc_packer import TcQueueT, PusTelecommand
 
+
 def pack_service5_test_into(tc_queue: TcQueueT) -> TcQueueT:
     tc_queue.appendleft(("print", "Testing Service 5"))
     # disable events
@@ -45,5 +46,9 @@ def pack_service17_test_into(tc_queue: TcQueueT) -> TcQueueT:
     tc_queue.appendleft(("print", "Testing Service 17: Trigger event"))
     command = PusTelecommand(service=17, subservice=128, ssc=1701)
     tc_queue.appendleft(command.pack_command_tuple())
+    # invalid subservice
+    tc_queue.appendleft(("print", "Testing Service 17: Invalid subservice"))
+    command = PusTelecommand(service=17, subservice=243, ssc=1700)
+    tc_queue.appendleft(command.pack_command_tuple())
     tc_queue.appendleft(("export", "log/tmtc_log_service17.txt"))
     return tc_queue