Preparation
Fiero Harness Removal
Follow the instructions accompanied with the photos to remove the Fiero harness.


You will only have to remove one of them in the Fiero.
as you can see here there are two harnesses entering the bulk head above the computer
First remove the nuts holding the computer in the holder there are four of them.
(see pointer)
Next remove the clip holding the bulk head connector in place (see pointer)
Then squeeze the clip on the bulk head connector and push the connector out
toward the engine bay. (See pointer)
Remove the computer connectors from the computer there are two. (One blue one red)
Remove the computer connectors from the computer there are two. (One blue one red)
disconnect the computer to body interface plug (see pointer)
Also remove the two screws holding the ALDL connector to the console (see pointer)
do not disturb the other harness . It is not necessary to do so. (see pointer)
Now that you have completed these steps you can now feed the harness through the fire wall and out of the engine bay.

Do not discard the old harness you will need it later.!!!!!!!!!!!
Fiero harness when removed
bulkhead connector after separation from the harness ( use a hair dryer to separate the connector halves and to remove the paste and wires from the connector so the new harness can be installed in it)


Fiero Computer Pin out
C1 red & white connector                                                                           C2 blue & black   
C1                                                                                                            C2
   1, blank                                                                                                  1,crank input
   2, speed input                                                                                      2,dist. reference pulse input
   3, ALDL                                                                                                  3, dist. ground
   4, blank                                                                                                  4, temp. input
   5, park neutral input                                                                          5, TPS sensor
   6, blank                                                                                                  6, blank
   7, ALDL                                                                                                  7, ac control relay
   8, injector control                                                                              8,O2 sensor
  9, blank                                                                                                  9, blank
 10, battery                                                                                            10, ignition module bypass control
 11, 5v reference                                                                                 11, ground
 12, ground                                                                                           12, IAC
 13, ground                                                                                           13, IAC
 14, ground                                                                                           14, blank
 15, battery                                                                                           15, ground
 16, ignition power input                                                                 16, blank
 17, blank                                                                                              17, IAC
 18, fuel pump                                                                                     18, IAC
 19, upshift light                                                                                 19,spark timing output
 20, service engine soon light                                                      20, map sensor
 21, ac on input
 22, blank


Body to Computer Connector C203
Fiero 2m4

A/ upshift light
B/ fuel pump power
J/ blank
C/ service engine soon
K/ blank
D/ blank
L/ blank
E/ oil light
M/ ground
F/ ignition power injectors
N/ blank
G/ blank
P/ blank
H/ speed output
R/ crank output

Fiero 2m6 & GT.

A/ up shift liter                                                                                       J/ injector power
B/ fuel pump power                                                                            K/ injector power
C/ service engine soon                                                                     L/ Fuel pump (brown white wire)
D/ blank                                                                                                  M/ ground
E/ oil pressure gauge                                                                        N/ ac control relay power
F/ key power for ECM                                                                        P/ TCL brake switch output
G/ speed sensor (yellow wire)                                                        R/ speed sensor (purple white wire)
H/ speed output (to ECM)






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