How To Repair Obd1 Honda Ecu At Controls The Iacv System

All common Honda and Acura D and B series engines use a ii wire Idle Air Command Valve (IACV). The two wire IACV uses one wire for power, and the other wire is for the idle command from the ECU. Even so, Honda made an exception to this on the 96-98 Civic DX and LX, and on the 96-98 Borough EX with automatic transmission by using a 3 wire IACV on these models. The iii wire IACV has one wire for power, the second wire for ground, and the third wire for idle command from the ECU.

All of our chipped/tunable OBD1 ECU solutions for the 96-98 civic use an ECU that is setup for a two wire IACV only. This makes it necessary to catechumen your Idle Air Command Valve to a ii wire style IACV anytime 1 of our tunable/chipped OBD1 ECU's are used.

The outset step is manifestly to switch out your 3 wire style IACV with a 2 wire IACV. This may require an intake manifold/throttle body change if yous still accept the stock engine installed. If you have washed an engine bandy with a B series engine or other D series engine that already has a 2 wire IACV, so this volition already be taken care of. If not, you volition need to install a 96-98 civic EX with manual transmission intake manifold, throttle body, and IACV or like.

Here's how to exercise the wiring:
Yous will need to source a ii wire IACV plug to replace your three wire iacv plug, and disconnect the ground wire from your idle air command valve wiring and re-pin the signal wires at the ECU plugs.

At the IACV plug:
one. Cut the orange wire and condone information technology or tape information technology off. It will no longer exist used.
2. Connect (solder/heatshrink) the yellow/blackness wire on your engine harness to the green/black wire on the replacement 2 wire IACV plug.
3. Connect (solder/heatshrink) the black/blue wire on your engine harness to the black wire on the replacement ii wire IACV plug.

At the ECU:
i. Locate connector "A" at your ECU.
2. Move the black wire with a bluish stripe from pin A14 to pin A12.
3. Remove the orange wire at pivot A13 and do not reinstall. But record this wire aside as it will no longer exist used.

Your engine and wiring is at present setup to use the 2 wire IACV plug. You lot can now connect your OBD2A to OBD1 ECU Jumper Harness and plug in your OBD1 ECU.