Hello, I am interested in learning about automotive electronics and I have some questions about car ECUs and how they work.
Firstly, what type of hardware and software does a cars engine control unit operate on? What is a typical micro architecture of a auto ECU? are the architectures common like ARM or MIPS or is it proprietary?
What type of ' operating system ' do they use?
I have read a very little about lookup tables and ROMS for car engine controllers, can you tell me more about these? what type of code are they written in? Assembly ?
Also how does the On-board Diagnostics system work?
1: where is the " host " or brains of the OBD2 system located? Is it a part of the main engine controller or a separate unit?
2: Does an ECU contain redundant self diagnosis circuitry? As in if a fault with the ECU occurs how can, or does it diagnose itself or would your OBD bus be offline/ dead?
3: is the ECU aware of other controllers on the vehicle? for instance if a fault occurs with another controller like the ABS or Airbag system, does the ECU know and does it relay this signal to OBDII port?
Are things like ABS, SRS Airbag, Electronic Stability / Electronic Traction control tested through the OBDII bus or do they have their own diag circuitry?
Firstly, what type of hardware and software does a cars engine control unit operate on? What is a typical micro architecture of a auto ECU? are the architectures common like ARM or MIPS or is it proprietary?
What type of ' operating system ' do they use?
I have read a very little about lookup tables and ROMS for car engine controllers, can you tell me more about these? what type of code are they written in? Assembly ?
Also how does the On-board Diagnostics system work?
1: where is the " host " or brains of the OBD2 system located? Is it a part of the main engine controller or a separate unit?
2: Does an ECU contain redundant self diagnosis circuitry? As in if a fault with the ECU occurs how can, or does it diagnose itself or would your OBD bus be offline/ dead?
3: is the ECU aware of other controllers on the vehicle? for instance if a fault occurs with another controller like the ABS or Airbag system, does the ECU know and does it relay this signal to OBDII port?
Are things like ABS, SRS Airbag, Electronic Stability / Electronic Traction control tested through the OBDII bus or do they have their own diag circuitry?