D16Z6 ECU wiring harness preparation:

1. Open up the cut up wiring harness’s loom from the donor car. All of the loom should be removed from the harness at this time so that you can easily access the wires.
2. Remove all wires that do not go to either the ECU connectors or the three main engine wiring harness connectors. You should just be able to pull them and they will slide out from the harness since they are not connected to anything. You shouldn’t have to cut anything at this point.
3. If you are using the Molex connectors then build the Molex #1 side A,15 pin connector as per the pin out below.

ECU connector (Molex #1) Pin out side A (Male side)

These are the wires coming from the new ECU’s wiring harness that need to be spliced into existing wiring that is on the car already. Most of which are cut off of the stock ECU’s wiring harness.

Molex Pin #	’95 ECU Pin #	ECU Wire Function
1	A7/A8	Fuel pump control signal                                        (GRN/YEL)
2	A9	Electronic air control valve signal                          (GRN/WHT)
3	A12	Radiator fan control signal                                      (YEL/GRN)
4	A13	Check engine light signal                                       (GRN/ORG)
5	A20	Purge control solenoid signal                                        (RED)
6	A23	PGM-FI Relay ground ties to A24                                  (BLK)
7	A24	Engine ground ties to A23                                             (BLK)
8	A25	Power to junction C125 tie to B1                            (YEL/BLK)
9	A26	Engine and data link ground                                  (BLK/RED)
10	B1	Power to junction C125 ties to A25                       (YEL/BLK)
11	B9	Starting input for ECU and PGM-FI relay             (BLU/WHT)
12	B10	Vehicle speed input signal                                      (YEL/BLU)
13	D1	Battery input (Hot at all times)                                (WHT/BLU)
14	D7	Data link connector (TXD and RXD)                        (LT. BLU)
15	D10	Electronic load detector signal                               (GRN/RED)

4. Cut the wires off of C451 (Plug A), C452 (Plug B), and C453 (Plug C) connectors from D16A6 ECU harness as you build the Molex #1 side B,15 pin connector. After you are sure that all the proper wires and connections have been made you can cut off the remaining wiring and pull out the stock ECU wiring harness. You will no longer need it after this point. Build the Molex connector for this side B as per the pin out below.

ECU connector (Molex #1) Pin out side B (Female side)

These are the wires that are cut off of the stock ECU wiring harness so that they can connect to the new ECU wiring harness

Molex Pin #	Harness wire color	Harness connection
1	GRN/BLK	Wire from C451 Pin #14 and 15
2	BLK	Run wire to Molex #2 pin 3 side A
3	YEL/GRN	Wire to C452 pin #12
4	GRN/ORG	Wire from C452 pin#13
5	BLK	Run wire to Molex #2 pin 5 side A
6	BLK	Wire from C451 pin #9
7	BLK	Wire from C451 pin #10
8	BLK	Run wire to Molex #2 pin 2 on the side A
9		Engine and data link ground
10	BLK	Run wire to Molex #2 pin 2 on the side A
11	BLU/WHT	Wire from C452 pin #7
12	YEL/RED	Wire from C452 pin #18
13	WHT/GRN	Wire from C452 pin #1
14		Data link connector
15	GRN/RED	Wire from C452 pin #10

Also be sure to connect the ignition timing check and data check connectors at this point as you will not pass smog if you do not have them!!! They may be disconnected or partially disconnected due to cutting at this point. These are a two-pin connector and a three-pin connector near the ECU some of the wiring might not be connected anymore so you will have to splice it back in where it belongs on the ECU harness.
 It’s not a big deal just follow the following wiring diagram below to verify that the connections are correctly made. The main thing to check is that pin 2 on the three pin connector has the wire running to a power source. I have chosen pin D1 as it is easy to access and in the same area saving you from running a wire somewhere to get 12Vs.