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Old 02-07-2010, 12:12 AM   #31 (permalink)
jfitzpat
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Quote:
Originally Posted by cfg83 View Post
It has been my impression that my 1999 ECU/PCM is slow to respond to commands.
A lot depends on the ECU and the protocol. OBD-II isn't really one protocol, it is more like 6, on top of three different electrical standards. The 'ISO' standards, which use the 'K' and 'L' lines are slow. There are a bunch of mandatory pauses between things that really bog things down.

J1850 and CAN are considerably faster, but there is still a lot of variation in response speed between different ECU's.

-jjf

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