Misc. OBD 1 Wiring Guides.

I will cover the following in this article:

So you want some Vi-TEChK yO?

If you are running a p28/p30, this applies to you. It may work on other OBD1 ECU/engine setups as well, but i'm not promising anything. Directly from the solenoid you will need to run the green/white wire to pin A4 on the ECU, which is the VTEC Spool Solenoid Valve Control. Next, connect the orange/blue wire to pin D6, which is the VTEC oil pressure switch input. Finally, the black wire from the VTEC pressure switch must be grounded. If you are running a USDM p30, make sure you wire up your knock sensor to pin location D3, otherwise VTEC will not engage.

So you want some IaBeeeS yO??? In order to make the Intake Air Bypass Solenoid activate when you swap a b18c1 into your civic/del sol you need to connect 2 wires. Coming from the solenoid there will be a yellow/black wire and a pink/blue wire. The yellow/black wire goes to the main pgm-fi relay and will see 12 volts constantly when the key is on. The pink/blue wire is what the ECU grounds to activate the solenoid and goes to pin A17.

So you want an Air/Fuel Ratio gauge huh?

Most of your typical A/F gauges will come with three wires. My autometer one had a red wire, a black one and a purple one. The red and black are self explanatory, just make sure the red goes to a 12v source that gets power only when the key is on. You can find one in the fuse box using a test light very easily. Ground the black wire. The purple wire will be the one that reads the O2 voltage. An O2 sensor sends a voltage between .0 volts and .5 volts to the ECU, we are going to splice into this and then your a/f gauge translates that into little colorful lights to make you extra cool. Splice your purple wire into the white wire going to ECU pin D14.

How to Check the Voltage on your Throttle Position Sensor.
After performing a swap, many times the throttle position sensor on the engine is broken, forcing you to use one from your old d15 or d16 (or whichever you pulled). The Honda TPS has three wires coming from it: green/white , a red/blue , yellow/white. Your primary focus will be on the red/blue wire, as this is the one that sends a voltage to the ECU telling it how open or closed your throttle is. The ECU expects .5 volts to be closed throttle and 4.5 volts to be Wide Open Throttle (WOT). The red/blue wire goes to pin D11 at the ECU. Rotating the TPS will change the voltage, when you take it off, you'll notice that the holes are slotted so it can move. If you are fortunate enough to have Hondata Datalogging or an Apexi V-AFC you can use their inbuilt functions to read the TPS voltage. If you do not have such a device, you can use a Voltmeter or similar device. Ground one lead on the chassis somewhere and use touch the (+) lead to the pin on the TPS (should be the center pin) and measure the voltage. Rotate it until it reads .5 volts, then tighten it down. Have a friend press the gas pedal to the floor and also check that WOT reads 4.5 volts.

For those interested with the other two leads, and I know there has to be someone out there. The green/white wire ties into a braided wire with the Intake Air Temp Sensor and the Heated Oxygen Sensor and they all run to Pin D22 on the ECU which is a sensor ground that reads less than 1 volt while the car is started. The yellow/white wire goes to pin D20 on the ECU which is a reference voltage, where it gives about 5v with the Key on and engine off.

if there is anything else you would like to see up here, please email me: pills@hondaswap.com

Return to Index page