4 ms·

The introduction of ECUs (electronic control unit) brought a lot of new problems to repair shops. And frankly many times they don't really know why something is

The introduction of ECUs (electronic control unit) brought a lot of new problems to repair shops. And frankly many times they don't really know why something is or isn't working. In the end it often comes down to replace all parts in an error chain such as the sensors, cables and sometimes the complete ECU. It's just a different world for a classic mechanic. Incidentally in a neighbour town a repair shop has popped up that has specialized in ECU repair. They developped a process to disassemble ECUs, dissolve the resin that contains the PCB and then do the repair on the boards.

maxerickson 5y ago
In the US, OBD II was mandatory in 1996. In that context, what's a classic mechanic?
- stonogo 5y ago
  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.
- pvaldes 5y ago
  We could see OBD as the car equivalent to USB port in computers. Classic cars from 40-70's don't have any way to be connected to an external computer (normally). Practically all modern cars (and none of the trucks) share the widespread OBD-II 16 pin connector. In the middle you can find a mess of different connectors in old cars from 80's and 90's when each brand was trying to produce their own unique plugs (You were forced to pay for their original software in the maker's official concessionaire). This was regulated later by laws to allow other companies entering in the market and for makers to reduce the mess. Electric cars could experiment a similar opening process, or not.
  - EamonnMR 5y ago
    Some cars with OBD 2 still require special connectors and software to fully explore the ECU. For example to properly connect to my Volvo you need a whole setup, to the point where an enterprising individual has made a business out of selling pre-installed software/hardware/laptop bundles: https://www.swedespeed.com/threads/vida-dedicated-laptops-for-sale.465809/ https://www.swedespeed.com/threads/vida-dedicated-laptops-fo...
  - jeffrallen 5y ago
    > Classic cars from 40-70's don't have any way to be connected to an external computer (normally). Allow me to blow your mind with the VW type 2 bus diagnostic port from my 1974 bus: http://www.speedyjim.net/htm/plug.htm http://www.speedyjim.net/htm/plug.htm But yes, even that port was analog, and was dropped in later models.
winrid 5y ago
Story time. I had one car about five years ago - a 1982 VW Scirocco. A 1.7L engine powered by mechanical fuel injection, controlled by an early ECU. It had a problem where the revs would bounce at idle like it had a big cam. Vroom VROOM vroom VROOM. Because of this, I got it very cheap. I realized if I opened and closed the hood it would stop. The ECU was mounted next to a hood hinge. Resoldering some connections for some capacitors fixed it. I ended up swapping in a modern turbo motor though. :)
gameswithgo 5y ago
shops have been equipped to deal with ecu equipped cars for decades. often it is even helpful, plug scan tool in, tells you which cylinder is lean or misfiring etc.

maxerickson 5y ago

In the US, OBD II was mandatory in 1996. In that context, what's a classic mechanic?

stonogo 5y ago
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.
pvaldes 5y ago
We could see OBD as the car equivalent to USB port in computers. Classic cars from 40-70's don't have any way to be connected to an external computer (normally). Practically all modern cars (and none of the trucks) share the widespread OBD-II 16 pin connector. In the middle you can find a mess of different connectors in old cars from 80's and 90's when each brand was trying to produce their own unique plugs (You were forced to pay for their original software in the maker's official concessionaire). This was regulated later by laws to allow other companies entering in the market and for makers to reduce the mess. Electric cars could experiment a similar opening process, or not.
- EamonnMR 5y ago
  Some cars with OBD 2 still require special connectors and software to fully explore the ECU. For example to properly connect to my Volvo you need a whole setup, to the point where an enterprising individual has made a business out of selling pre-installed software/hardware/laptop bundles: https://www.swedespeed.com/threads/vida-dedicated-laptops-for-sale.465809/ https://www.swedespeed.com/threads/vida-dedicated-laptops-fo...
- jeffrallen 5y ago
  > Classic cars from 40-70's don't have any way to be connected to an external computer (normally). Allow me to blow your mind with the VW type 2 bus diagnostic port from my 1974 bus: http://www.speedyjim.net/htm/plug.htm http://www.speedyjim.net/htm/plug.htm But yes, even that port was analog, and was dropped in later models.

winrid 5y ago

Story time. I had one car about five years ago - a 1982 VW Scirocco. A 1.7L engine powered by mechanical fuel injection, controlled by an early ECU. It had a problem where the revs would bounce at idle like it had a big cam. Vroom VROOM vroom VROOM. Because of this, I got it very cheap. I realized if I opened and closed the hood it would stop. The ECU was mounted next to a hood hinge. Resoldering some connections for some capacitors fixed it. I ended up swapping in a modern turbo motor though. :)

gameswithgo 5y ago

shops have been equipped to deal with ecu equipped cars for decades. often it is even helpful, plug scan tool in, tells you which cylinder is lean or misfiring etc.