My x brake down on the road today and show 'Engine Failsave Prog' in the dash board. When I started the engine when it is hot, it shut down after the engine started. Anyone knows what the problem is? When I started the engine when it is cold, it ran like someone kept push and release the accelerator. Please help me!!!

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--2004 E53 X5 4.8is - ECE version; right hand drive; Located in Hong Kong; ext. black sapphire metallic; int. leather black; adaptive dynamic bi-xenon headlights; 16:9 onboard monitor w/o navigation; 20" genuine BMW Y-spoke 214 wheels with Bridgestone Dueler H/P Sport tires; Int. rear view mirror w/ compass.