I have a 1991 rx7 vert and the check engine light was on. I scanned it and got a code saying that the problem was the computer was malfunctioning. Also I got a 30 which is the split air solenoid which I herd you have to replace the whole air control valve. I have a new computer on the way because the mechanic said to start with that. Where is the computer located and where is the air control valve located so i can replace them. Also is the computer just a plug in. It's from another fc vert

 

The error code for the computer is a bit confusing, what was the specific error code? And the error code for the solenoid probably means the connection to the solenoid is poor. And the ACV shouldn't have to be replaced.

 

where is the solenoid. And i'll get back to you with the code for the computer

 

There are two solenoids at the ACV and one of them is the Split Air and it has two wires, one is Black/White and has 12 volts w/key to on and the other wire is Blue/Black and has 12 volts as well w/key to on and the voltage is supposed to drop below 2.5 volts w/the car in 5th gear (pin 3I of the ECU is for this solenoid). The Blue/Black wire should be checked at the ECU.

 

The code is number 14 for the ecu

 

Code #14 is for the Atmospheric Pressure Sensor which is located within the ECU of an S5 so it now makes sense how you were told that the computer was problematic. The ECU is located under where the passenger's feet would rest.

 

Is it a plug in an move on deal or do I have to take it to a mechanic for anything

 

It's a simple unbolt/unplug and install the replacement. And of course always disconnect the negative battery terminal before doing so.

 

It's actually great that you said to disconnect the battery because i didnt know you had to for this install. Do I have to get the light cleared afterward

 

You can have the code cleared but if the problem isn't solved it will return.

 

You're replacing the ECU so there shouldn't be any info stored on the newer ECU. There's constant voltage running to an S5 ECU so it can store codes so this is why you disconnect the battery so as to prevent damage to the newer unit upon installation. If you didn't do anything to fix the code 30 you previously got then the new ECU should pick up on that, and when putting in the new ECU you check pin 3I as previously suggested to see what's causing that error code.

 

How do i tell which one is pin 31. Does it say it

 

Use the wiring diagram and it will tell you which is plug 3 of the ECU and where in the plug is pin 3I. You were given the wire color so that really narrows it down for you. Looking at the plug as it is plugged in, pin 3A is top right. Below that is pin 3B so just to the left of 3A would be pin 3C and right below that is pin 3D and so on, thus 3I would be top row and 5th from the right.

 

Thank you. I thought it said pin 31 not 3I

 

Is it under the metal pan under the carpet?

 

Yes.

 

Replaced ecu. Bonus the new one has a jet performance chip. No check engine light. Feels alot peppier too. Thanks for the help everyone