diff --git a/phosphor-power-supply/power_supply.cpp b/phosphor-power-supply/power_supply.cpp
new file mode 100644
index 0000000..a6be9f5
--- /dev/null
+++ b/phosphor-power-supply/power_supply.cpp
@@ -0,0 +1,58 @@
+#include "power_supply.hpp"
+
+#include "types.hpp"
+#include "utility.hpp"
+
+namespace phosphor
+{
+namespace power
+{
+namespace psu
+{
+
+using namespace phosphor::logging;
+
+void PowerSupply::updatePresence()
+{
+    try
+    {
+        // Use getProperty utility function to get presence status.
+        util::getProperty(INVENTORY_IFACE, PRESENT_PROP, inventoryPath,
+                          INVENTORY_MGR_IFACE, bus, this->present);
+    }
+    catch (const sdbusplus::exception::SdBusError& e)
+    {
+        // Relying on property change or interface added to retry.
+        // Log an informational trace to the journal.
+        log<level::INFO>("D-Bus property access failure exception");
+    }
+}
+
+void PowerSupply::inventoryChanged(sdbusplus::message::message& msg)
+{
+    std::string msgSensor;
+    std::map<std::string, sdbusplus::message::variant<uint32_t, bool>> msgData;
+    msg.read(msgSensor, msgData);
+
+    // Check if it was the Present property that changed.
+    auto valPropMap = msgData.find(PRESENT_PROP);
+    if (valPropMap != msgData.end())
+    {
+        if (std::get<bool>(valPropMap->second))
+        {
+            present = true;
+            clearFaults();
+        }
+        else
+        {
+            present = false;
+
+            // Clear out the now outdated inventory properties
+            updateInventory();
+        }
+    }
+}
+
+} // namespace psu
+} // namespace power
+} // namespace phosphor