diff --git a/attn/ti_handler.cpp b/attn/ti_handler.cpp
index 4801f2c..f1354aa 100644
--- a/attn/ti_handler.cpp
+++ b/attn/ti_handler.cpp
@@ -1,27 +1,36 @@
+#include <attn_handler.hpp>
 #include <attn_logging.hpp>
 #include <sdbusplus/bus.hpp>
+#include <ti_handler.hpp>
 
 namespace attn
 {
 
 /** @brief Start host diagnostic mode systemd unit */
-void tiHandler()
+int tiHandler(TiDataArea* i_tiDataArea)
 {
-    // trace message
-    trace<level::INFO>("start host diagnostic mode service");
+    int rc = RC_NOT_HANDLED; // assume TI not handled
 
-    // Use the systemd service manager object interface to call the start unit
-    // method with the obmc-host-diagnostic-mode target.
-    auto bus    = sdbusplus::bus::new_system();
-    auto method = bus.new_method_call(
-        "org.freedesktop.systemd1", "/org/freedesktop/systemd1",
-        "org.freedesktop.systemd1.Manager", "StartUnit");
+    if (0xa1 == i_tiDataArea->command)
+    {
+        // trace message
+        trace<level::INFO>("start host diagnostic mode service");
 
-    method.append("obmc-host-diagnostic-mode@0.target"); // unit to activate
-    method.append("replace"); // mode = replace conflicting queued jobs
-    bus.call_noreply(method); // start the service
+        // Use the systemd service manager object interface to call the start
+        // unit method with the obmc-host-diagnostic-mode target.
+        auto bus    = sdbusplus::bus::new_system();
+        auto method = bus.new_method_call(
+            "org.freedesktop.systemd1", "/org/freedesktop/systemd1",
+            "org.freedesktop.systemd1.Manager", "StartUnit");
 
-    return;
+        method.append("obmc-host-diagnostic-mode@0.target"); // unit to activate
+        method.append("replace"); // mode = replace conflicting queued jobs
+        bus.call_noreply(method); // start the service
+
+        rc = RC_SUCCESS;
+    }
+
+    return rc;
 }
 
 } // namespace attn