What can be checked with onboard diagnostic? How does it work?

Answer 1

With a proper scan tool (not a code reader) on an OBDII vehicle a technician can view all engine parameters and sensor performance in real time and can do other fun stuff like command the EGR valve to open on command. The other day for example I had the scanner hooked up to a truck that did not have a check engine light on but found that the Throttle Position Sensor was always reading 0% open even when you floored it. That wasn't even the problem I was looking for.

Answer 2

Wow, well i cant give you a complete list but here is a brief overview. I am assuming you are talking about scanning the vehicle. You can a numer of Modules. PCM (powertrain) TCM (transmission) ABS, Body Control Module. Basically these Modules control many actions in the vehicle, they monitor its progress and set codes if they detect any problems. They can show engine misfires, transmission slippages, Emissions leaks, electriacal shorts. Their really are to many to name. Basically your car is one big computer and the onboard diagnostics or OBD helps technicians figure out what is wrong

Answer 3

The amount of information you can download from a modern vehicle is staggering, i work on the Mercedes Training programme and we use a system called star and das, on each vehicle including trucks there area number of sensors and control modules that operate the systems on the vehicle. We regularly download data which tells us how the vehicles are operating and it also stores faults on the onboard memory so we can read them and locate the problem

Answer 4

From my understanding it basically targets the area in the car where the problem is. This way they just check that specific part of the car to fix it.

Answer 5

every sensor in the vehicle can be checked with obd2. all the sensors are tied into the computer and you are plugging right into the computer.

Answer 6

http://www.obdii.com/obdii.asp

http://www.autotap.com/technical_library.asp

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