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>> An electric only latch would reduce parts count I disagree. Dozens of parts are needed simply to bring an electric wire into a door. Every penetration nee

>> An electric only latch would reduce parts count I disagree. Dozens of parts are needed simply to bring an electric wire into a door. Every penetration needs grommets and strain relief. A flexible weatherproof system needs to get the wire from the door to the rest of the car. Relays. Fuses. It all adds up. I cannot believe that a manually-actuated lever would require any more parts.

hengheng 3y ago
There are two kinds of engineers in the mechanical and electrical departments. One says "If we just run wires / automate / motorize it will be easier", and they see the direct path from start to finish that matches the requirements. Then there are those who say "every wire complicates compliance testing, every automation complicates failure modes, every custom part complicates supply chain", and they are the ones that prefer in-house mechanical parts with conservative materials and tooling. I think it's an age thing, maybe it's a hipster vs greasy-elbows-shop-floor guy thing, but honestly it can be hard to tell who's right.
- OrigamiPastrami 3y ago
  I think it's mostly an issue of experience. Younger engineers tend to make things more complicated than they need to be and are unaware of reliability issues. Older engineers better understand tried-and-true systems and are more likely to want to stick with things they know work well. Obviously I'm speaking generally and individuals vary greatly.
- tomxor 3y ago
  There's another angle: system independence. When things go wrong, i.e in a crash, you still want to guarantee an undammaged door latching mechanism can still be operated independent of other parts of the car being damaged (likely). To satisfy this for a purely electrically actuated latch you would need a battery and independent controller in every door. It's hard to beat the reliability of a mechanical latch and a human hand to satisfy that requirement.
bombcar 3y ago
You already have power in the door, because a car without power windows is a non-starter these days. And power locks. So using the electricity already present for the door handles has to be entirely tempting.
Lord_Zero 3y ago
Sure but in most cases, there's ALREADY wires going to the window motors and locks. In this situation, removing the mechanical door handle/latch operation does indeed simplify things.
83 3y ago
>> Every penetration needs grommets and strain relief. You mean the grommets and strain relief that are already present for windows/speakers/locks? In most cases it's probably not even additional wires as power and control (either can bus or lin bus) are already established from the door to bcm (body control module).

hengheng 3y ago

There are two kinds of engineers in the mechanical and electrical departments. One says "If we just run wires / automate / motorize it will be easier", and they see the direct path from start to finish that matches the requirements. Then there are those who say "every wire complicates compliance testing, every automation complicates failure modes, every custom part complicates supply chain", and they are the ones that prefer in-house mechanical parts with conservative materials and tooling. I think it's an age thing, maybe it's a hipster vs greasy-elbows-shop-floor guy thing, but honestly it can be hard to tell who's right.

OrigamiPastrami 3y ago
I think it's mostly an issue of experience. Younger engineers tend to make things more complicated than they need to be and are unaware of reliability issues. Older engineers better understand tried-and-true systems and are more likely to want to stick with things they know work well. Obviously I'm speaking generally and individuals vary greatly.
tomxor 3y ago
There's another angle: system independence. When things go wrong, i.e in a crash, you still want to guarantee an undammaged door latching mechanism can still be operated independent of other parts of the car being damaged (likely). To satisfy this for a purely electrically actuated latch you would need a battery and independent controller in every door. It's hard to beat the reliability of a mechanical latch and a human hand to satisfy that requirement.

bombcar 3y ago

You already have power in the door, because a car without power windows is a non-starter these days. And power locks. So using the electricity already present for the door handles has to be entirely tempting.

Lord_Zero 3y ago

Sure but in most cases, there's ALREADY wires going to the window motors and locks. In this situation, removing the mechanical door handle/latch operation does indeed simplify things.

83 3y ago

>> Every penetration needs grommets and strain relief. You mean the grommets and strain relief that are already present for windows/speakers/locks? In most cases it's probably not even additional wires as power and control (either can bus or lin bus) are already established from the door to bcm (body control module).