3 Jul
2004
3 Jul
'04
6:07 p.m.
It was thus said that the Great Tony Duell once stated:
Alas the manuals I've seen don't explain the internals of the ECUs
(Electronic Control Units), they don't document the protocol for the
diagnostic tester. So you still have to buy some overpriced readout tool
to get the fault codes... Things were simpler 20 years ago when 99% of
engice faults could tbe traced with a compression tester, timing light
and Colourtunr (that's a sparking plug with a transparent glass
insulator, so you can observer the mixture burning in the cylinder. It's
one of the best things I know for tracing carburetter problems).
I have a friend that writes car diagnostic software and from what he's
told me so far (at least in the US) there are several different protocols in
use (some as slow as 5 baud; I forgot what the fastest was) and about the
only thing that's been standardized right now is the diagnostic connector,
and it's location (beneath the steering column) and the pin outs for each
major manufacturer (Ford gets pins x,y and z, while GM gets pins a,b,c and
d, stuff like that).
He's having a blast, and it's amazing just how computerized cars are
nowadays (his cow-orker is able to control every aspect of a car's operation
(including wipers!) except for steering and on a manual, the transmission)
and that for modern cars it's not unusual to have up to 40 addressable units
within the car. He also says that you can get programs specific to the
locale you live in (here, that would be a flat, sub-tropical locale, being
we both live in South Florida) and that such programming can increase gas
milage, but you have to ask the dealership specifically for such
programming.
Neat stuff, but for me, all second hand information ...
-spc (To think there's a network in my car ... )