Bosch HBB-EP31-7 Top Oven/ Grill Fault

Need help to pin point the faulty component in my Bosch double electric Oven. Oven is about 12 years old and worked extremely well over the years.
Our house electric started tripping and ultimately the caused identified the faulty heating element of the main oven which was changed and main oven start working without electric tripping. However there is another minor fault developed in the top oven grill side of the equipment. Temperature control of the top oven becomes abnormal, now after the use of grill or oven turning both nobs to off positions but still on/off LED quite faintly lit. We have also noticed that once or twice it was still heating even my wife turned it off. Now the LED that indicated the on/off status turned off if we select higher temperature depending on time we turned turn off position and temperature of the oven.
I suspected that might be cable connections were made incorrectly at the temperature controller when main oven heating element changed or some other part need to change? Your help and guide in this matter will much appreciate. Any service document to check the wires connection at the top oven temperature controller and oven/grill switch?
Please help.