I went through all the archives and pulled all this information together.
I now have the "know how". All I need now is a custom chip for the ECM
REPROGRAMMED PROM REQUIRED
The 85 ECM has the capability to handle inputs from the GM ESC module with a knock sensor input. The PROMs from the 6869 ('85) and 7170 ('86-'88) ECMs aren't compatible. In addition to adding the hardware and wiring it in, you will need a new chip programmed to have the knock sensor feature flag enabled. Without a new chip, this setup won't work.
PARTS
'85 GT ECM - GM part # 1226869
Knock sensor is GM part # 10456287
Knock sensor harness connector is GM part # 12102621
2 BAR Map sensor is GM part # 12569241 (AC Delco 213-361)
Map sensor pigtail and lead GM part # 15305891 (AC Delco PT-1035)
ESC module is GM part # 16126761 brodcast code ANRZ
ESC harness connector is GM Part # 12101871
WIRING
On the module you have 5 pins. These pins are labeled A, B, C, D, and E.
ESC signal is fed into terminal B7 of ECM harness.
Wire them into the computer as follows:
A = Not used on Fiero application
B = ECM B1 (power)
C = ECM B7 (knock input)
D = ECM A12 (ground)
E = Connect to Knock Sensor
Links to forums...
85 ECM & knock sensor
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20030531-2-030008.html
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20031110-2-036541.html
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Another way is to use an ESC Controller and knock sensor from a 1978-80 non-ECM turbo Buick.
This is a "stand-alone" that can be added into existing wiring to directly control the signal distributor.
See here http://home.flash.net/~rjgeorge/knock.htm
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3.4L S/C 87 GT www.fierosound.com
2002/2003/2004 World of Wheels Winner &
Multiple IASCA Stereo Award Winner
[This message has been edited by fierosound (edited 08-13-2004).]
