LT5 Info.., and 1228331 stuff in general.

["Bruce Plecan" <nacelp@bright.net>]

For those of you interested in the LT5 and it's (90 MY) ecm here's some info
that just reached CSH, HQ..

It is DIS, and the module only uses a crank signal.
The cam signal is feed to the ecm for the SEFI.

The ecm turns the power on to a set of relays (to power them up at, @
WOT/High demand injectors), which ground thru the ecm like the first set of
8 do.

The secondary air valve is solenoid operated, so it might be progessive.

*** I mention this only since it was reported early (much) that they
(injectors/butterfly) were a bang, bang affair (not progressive).***

It is a MAP system.

It monitors oil temp, and sec port vac..

It drives a Engine Full Power Light  (hmm, no comment about that one)......

There is a secondary Fuel Pump Driver (it operates a relay for the pump).

The "line" that looks like what would be the normal sync line to the ecm is
a DIS Failure connection.

It uses a seperate ESC Module!.

If the serial data line is wired like I think it is good luck on getting it
to work.
On the 86ish tornados they had the same deal with lots of MPUs that talked
on the same line.  It was a joke.  Period, gm couldn't get it to read right
on a scanner (at that time).  While some of the other MPUs have a seperate
ALDL tap, they might be dependent on the ECM for when to talk, or pause.

A complete, and total hac of that code would have to be interesting reading.
Grumpy