ISO9141

[martin at mgass.demon.co.uk]

Anybody able to throw more light on the initiation sequences of the 
above protocol.

Using a VB4 Program I am montoring comms between a laptop with 
a ScanTool on it and the J1962 connector.  I also have a VB4 
program emulating an ECU (connected straight to scantool using rs232).

I know the theory about grounding the K or L line or both (or tx a one 
byte address at 5 bps). And the ECU replying with 55h at specified baud 
rate.

At the moment I see the scan tool do the following (at rs232 level)
-Change CTS
-Change RI
-Send Break
It then reponds to a Break sent back to it.

What is the next sequences in the protocol ?

I know about ISO-9141-2 etc, but don't have a copy just yet.

I am particulalrly interested in any deviations from the Spec for 
European GM Vehicles.

regards,

Martin
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martin at mgass.demon.co.uk
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