diff --git a/pyren/mod_elm.py b/pyren/mod_elm.py
index 3e62571..ff83f1e 100644
--- a/pyren/mod_elm.py
+++ b/pyren/mod_elm.py
@@ -1820,7 +1820,7 @@ class ELM:
         self.check_answer(elm_ver)
 
         # check STN
-        st_rsp = self.cmd("STPR")
+        st_rsp = self.cmd("STP 53")
         if '?' not in st_rsp:
             mod_globals.opt_stn = True