2G P1500 Code

[Talontuner1995]

Hello Tuners. So I pulled a p1500 code and also a IAC code from my 95 talon tsi the other day. Vehicle has been holding steady from 3 to 4 thousand RPM when the engine is up to operating temprature. This is an intermintent problem. I have replaced the idle air control motor and still didnt fix the problem. I have been doing a little research and have came to the conclusion that it is either my computer or my alternator. I have ran through the dealer diagnosis flow chart and have determined that my alt is bad. What is throwing me off is now when i hook up my code reader it is not letting me access my codes anymore. Fuse is good to the OBD2 Conecter. But still telling me to reconnect or to cycle my key witch neither work. Also not sure if this is related to the code but had an issue where my car wouldn't start. You could hear it trying to fire up. Had to feather the gas pedal to increase RPM while doing so it was missing horribley. Once I babied it up to about 1500 RPm it smoothed out then proceded to rev to the 3-4 KRPM range. Any helpful info would be great or any kinda forsure tests that will help me rule out one or the other because i dont wanna drop the money for one part and it be the other as they are both a little expensive.

 

[evoredy]

I'm surprised the common brake and battery lights aren't on with this issue. Check the wiring carefully for the alternator regulator (should be a connector right in front). Disconnect your battery when you're doing all of this. Also, check the main alternator power wire.

The OBD scanner is probably not detecting enough voltage to begin like <12 volts or so with key-on. Along with that, look at your under hood fuse box and make sure the large fuses (post #4) aren't melted.

This is also a good thread on this.

I'm leaning towards alternator or wiring. I'm sure you'll figure it out.