MemCals Needing a Good Home...

[Ludis Langens]

Walter Sherwin wrote:
> 
> The NETRES is part of an analog complex circuit which attempts to drive the
> physical hardware in the event of either a CPU failure or an EPROM failure.
> [...]  Yes, it requires that
> the hardware is "okay"  and specifically it assumes that the TPS, CTS, and
> MAP (or MAF) are okay.

Actually, on MAF cars, only TPS and CTS are used.  If you study the
wiring harness diagrams for both MAF and MAP 2.8 MPFI's (1226869 &
1226870 ECMs), you'll notice that either MAP or TPS goes to two ECM
inputs.  The extra input goes to the RFD chip.  In a P4, the MEMCAL can
jumper TPS into a circuit that creates a fake MAP signal.  Look at pins
61, 63 & 64 of the MEMCAL.  Pin 61 provides the LOAD signal to the RFD. 
63 & 64 are hooked to the raw MAP and TPS signals.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
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