When the engine is running, it displays 2 signs on the dash board [Landar sign as in Mathmatics and abs]. could this possibly mean fault?.how could i fix the sound system, back speakers will not respond.[model CR 606].does the vehicle has thermostat in the water cooling system? is it normal to run the vehicle on Nigerian weather since it is predominantly hot?.one of the front doors wont respond when the main door is opened with the key but it does lock.