4 ms·

OBD-II only requires the car be able to report faults related to emissions. You can (and many did) build cars without central computers and still provide OBD-I

OBD-II only requires the car be able to report faults related to emissions. You can (and many did) build cars without central computers and still provide OBD-II compliance. For a long time, even if there was an ECU it might only have been handling injection and ignition timing. The modern approach, where a car is essentially a computer with some mechatronic peripherals related to making the wheels turn, is relatively recent even now.

maxerickson 5y ago
So? A mechanic working 25 years ago had more than a little bit of incentive to understand electronic control systems. That's my point. Is the idea that we should build cars so that dead people have an easy time servicing them?
- topkai22 5y ago
  I suspect the OP was making a historical analogy to the past experience of the ECU transition. The ECU transition was disruptive and caused pain for both mechanics (who had to reskill) and consumers (who had to deal with a market full of mechanics who didn’t necessarily know what they were doing for a long time.)
  - totalZero 5y ago
    I think this is an overly abstracted view of how transitions work. In reality, most trades are experiential-apprenticeship businesses, and technology advances slowly. For example, a 15-year-old car may run ignition with a distributor, while a newer one may have coil packs that receive signals from MOSFETs in the engine computer assembly. Fixing those two systems can be totally different despite the fact that both have engine control computers. Technological advance is not a step function and describing every transition as disruptive is not particularly meaningful even when it is true.
  - PeterisP 5y ago
    I haven't really seen mechanics reskill, what local shops seem to do is to employ separate "electronics people" as another specialization - like they already had bodywork handled by separate people who do all the bodywork and nothing else; so now they have "classic mechanics" working on the mechanical parts (which, frankly, is most of the work) and whenever OBD shows something nontrivial they hand it off to someone who does nothing else but debugging ECUs and sensor/wiring issues.
BelenusMordred 5y ago
> only requires the car be able to report faults related to emissions I'm just a layman who dabbles in diy car repair but from my experience with a cheap Chinese bluetooth obd-ii interface and an android app it reports far, far more than that. There's almost an obscene amount of data, and this was with an old car that was made only a few years after obd was released. I don't think this statement is correct.
- pvaldes 5y ago
  The point is in "required". The makers can do the car report anything that they want, but older cars often report the bare minimum. If your car has android is modern. The difference between a car made before 2000 and a car from 2005 is huge. Cars currently are really sophisticated computers with tires. There are a lot of systems all managed by the central ECU. Things like airbag, electric windows, seat heaters, electronic brakes, ABS, coolant circuit... each one are managed by its own circuit. Not needing oil changes or air flow meters for the mix, electric cars will be much more simplified in some parts but I bet that are absolutely arcane in the other. And the battery can kill you easily.
  - BelenusMordred 5y ago
    > if your car has android is modern. I think you misunderstood, I bought a cheap bluetooth obd2 device and accessed the data from an open source android app. It was a 2004 model from memory, the amount of data you could glean from that blew my mind back then. Older and easily serviced cars are fun, most things you can do yourself with a service manual. For a few things like changing brake discs I got a mobile mechanic to come to my house to do it and teach me at the same time. You don't need many tools to get started. Working on your own vehicle is a very self-reassuring hobby.
    - pvaldes 5y ago
      I stand corrected then. Thanks I agree that the amount of info is incredible. The problem of the cheap diagnoses machines are that they aren't always updated. Not to mention the market flooded with pirated products that can made more harm than good. Many cars share the same error codes for very different things so interpretation is also a tricky issue. Translation in chinese machines is often of bad quality also. Professional diagnose machines play in a different league and are really expensive.

maxerickson 5y ago

So? A mechanic working 25 years ago had more than a little bit of incentive to understand electronic control systems. That's my point. Is the idea that we should build cars so that dead people have an easy time servicing them?

topkai22 5y ago
I suspect the OP was making a historical analogy to the past experience of the ECU transition. The ECU transition was disruptive and caused pain for both mechanics (who had to reskill) and consumers (who had to deal with a market full of mechanics who didn’t necessarily know what they were doing for a long time.)
- totalZero 5y ago
  I think this is an overly abstracted view of how transitions work. In reality, most trades are experiential-apprenticeship businesses, and technology advances slowly. For example, a 15-year-old car may run ignition with a distributor, while a newer one may have coil packs that receive signals from MOSFETs in the engine computer assembly. Fixing those two systems can be totally different despite the fact that both have engine control computers. Technological advance is not a step function and describing every transition as disruptive is not particularly meaningful even when it is true.
- PeterisP 5y ago
  I haven't really seen mechanics reskill, what local shops seem to do is to employ separate "electronics people" as another specialization - like they already had bodywork handled by separate people who do all the bodywork and nothing else; so now they have "classic mechanics" working on the mechanical parts (which, frankly, is most of the work) and whenever OBD shows something nontrivial they hand it off to someone who does nothing else but debugging ECUs and sensor/wiring issues.

BelenusMordred 5y ago

> only requires the car be able to report faults related to emissions I'm just a layman who dabbles in diy car repair but from my experience with a cheap Chinese bluetooth obd-ii interface and an android app it reports far, far more than that. There's almost an obscene amount of data, and this was with an old car that was made only a few years after obd was released. I don't think this statement is correct.

pvaldes 5y ago
The point is in "required". The makers can do the car report anything that they want, but older cars often report the bare minimum. If your car has android is modern. The difference between a car made before 2000 and a car from 2005 is huge. Cars currently are really sophisticated computers with tires. There are a lot of systems all managed by the central ECU. Things like airbag, electric windows, seat heaters, electronic brakes, ABS, coolant circuit... each one are managed by its own circuit. Not needing oil changes or air flow meters for the mix, electric cars will be much more simplified in some parts but I bet that are absolutely arcane in the other. And the battery can kill you easily.
- BelenusMordred 5y ago
  > if your car has android is modern. I think you misunderstood, I bought a cheap bluetooth obd2 device and accessed the data from an open source android app. It was a 2004 model from memory, the amount of data you could glean from that blew my mind back then. Older and easily serviced cars are fun, most things you can do yourself with a service manual. For a few things like changing brake discs I got a mobile mechanic to come to my house to do it and teach me at the same time. You don't need many tools to get started. Working on your own vehicle is a very self-reassuring hobby.
  - pvaldes 5y ago
    I stand corrected then. Thanks I agree that the amount of info is incredible. The problem of the cheap diagnoses machines are that they aren't always updated. Not to mention the market flooded with pirated products that can made more harm than good. Many cars share the same error codes for very different things so interpretation is also a tricky issue. Translation in chinese machines is often of bad quality also. Professional diagnose machines play in a different league and are really expensive.