Jaguar XKR Restricted Performance Fix: How to Perform a Battery Hard Reset

Chasing a "Restricted Performance" ghost on my Jaguar XKR! After replacing shims and spark plugs, the engine was still misfiring on all eight cylinders and refusing to idle. Today, I’m trying the "Hard Reset" procedure [03:15] to see if the ECU just needs to re-learn its factory defaults. ​I’ll walk you through the process of safely performing a battery hard reset [06:23] and resetting the window limits [15:09]. Watch as we clear the OBD2 fault codes [09:25] and see if this simple trick finally gets the XKR to idle smoothly for the first time! ​In this video: ​The Diagnostic: Pulling fouled spark plugs and identifying misfire codes [01:14]. ​The Hard Reset: Touching terminals to discharge the ECU and clear adapted memory [06:23]. ​The Results: Watching the rev counter stabilize and the "Restricted Performance" light vanish [13:25]. ​Maintenance Tips: Resetting windows and cleaning up blackened spark plugs [15:09]. ​If you're a Jaguar enthusiast or a DIY mechanic, Subscribe to see the rest of this X100 restoration! ​🔔 Subscribe for more Jaguar restoration videos 💬 Comment below: Have you ever used a hard reset to fix electrical gremlins in your Jag? ​#JaguarXKR #X100 #JaguarRepair #RestrictedPerformance #HardReset #ECUReset #DIYMechanic #ProjectsInTheBarn ​3. Video Chapters ​[00:00] Intro: Chasing Persistent Misfire Issues [01:14] Inspecting Blackened Spark Plugs & Misfire Codes [02:11] Why These Jaguars Need a Strong Battery [03:15] The Logic Behind a Jaguar Hard Reset [04:41] Preparing the Engine Bay & Boot for the Reset [06:23] Step-by-Step: Safely Performing the Hard Reset [07:45] Reconnecting the Battery (Will it Explode?) [08:12] Initial System Check: Restricted Performance Still Active? [09:25] Clearing OBD2 Fault Codes (Misfires on 8 Cylinders) [11:10] First Start After Reset: Searching for Idle [13:25] Success! Stable Idle & Light Goes Out [15:09] How to Reset Jaguar Window Memory [17:03] Examining the Condition of the Spark Plugs [18:38] Finding the Next Problem: Brake Fluid Leak [20:18] Conclusion: The Road to Restoration is Open!