i scanned the car and got this code, P1637 Generator L-Terminal Circuit i try deleting it and it keeps on coming back, anyone know what exactly it means, i been googleing it and it seems like everything is in Chinese i need help plz. thanks in advance.

 

I already told you what to check for Danny.

 

I Did, checked grounds, bought a new alternator, battery terminals are all good and cleaned, the alternator plug is good... don't know what else it could be. hey Jason u left the pcm cover off, also in the passenger kick panel the wires u were messing with, there r 2 wires unplugged but i don't have a clue where they came from and the purpose of them, lmk when u can check it out plz. thanks!

 

quick thing, i did what this guy says not to do "Do not disconnect the battery with the engine running. ECM controlled cars don't put up with that. As soon as the PCM senses the voltage drop it will stop spark and fuel. Keep in mind that the battery is the only power source, the alternator simply provides "charging current" that is voltage specific and limited. As you car places a load on the electrical system, it uses battery juice and the alternator is constantly replacing it. Get youself the alternator overdrive pulley and the proper belts and you'll be okay." -SOME RANDOM DUDE

Anyways i had a dead battery and my voltage gauge was really low, i replaced the alternator with a new one, before i did that i did turn on the ignition had the car running and unplugged the battery's power cable to see if the car would turn off, i had no idead that this wasn't recommended for this cars, now i have this Fk'n code, i tried running the car for about 30 mins and nothing happens its still there. anyone have a clue of whats happening or what could of happened?

 

Does this code effect performance noticeably or at all D Boy? Also what condition were your plug wires in, did you take them off and inspect them lastnight? I sitll got these 4 on stand by if you want to try them.

 

when you are deleting the code are you doing it with the engine running or engine off, ignition on?
pretty much w/ the ignition on ,engine off, you will see a very low voltage at the l terminal to the pcm...the terminal needs to see low voltage (windings magnetized) in order for the generator to be able to begin "working".
once the engine is running, and the alternator is producing current, the circuit will see ignition voltage...
so, you need to check for low voltage at the terminal w/ the engine off, ignition on...
and operating (ignition ) voltage while the engine is running...its easy to test right off the alternator terminal, to see if the alternator is functioning properly...
its not a bad idea to also do voltage drop across from pcm to terminal to ensure there are no faulty connections...
you would need to check twice...once w/ engine off, ignition on... once with engine running...just remember, circuit needs to be "working" in order to do voltage drop.

 

My car has thrown that code for the last 2 years every time i scanned it, have no idea what it causes

 

have u had any BS problems?

 

i did it both ways, nothing happens i mean it clears the code but right after i rescan it, its still there. ill try your idea this weekend.

 

the wires seemed alright i didnt check the back 2 because it was too late, but i noticed they reused ALL the MSD wires, (remember Bryce gave me a cheap *** one cus one of the wires was fucked) so yeah im just gonna order a new set. i hope it fixes the problem. Thanks Alex!

 

The only PS problems ive had was when i first put the new cammed motor in my alternator took a ****, but we think that might have been RPM related on a 66K mile alternator/it went out the same time my red top did so were chalking it up to no L Terminal related problems

 

Hey I can take a look at it for you when you pick up the parking brake handle.

 

thats cause you have a race car now.......

come pick up that race cell already ...... and you can swap my LED tail lights for your factory ones lol

 

its actually gone, when can i go get the p-brake Ivan?

 

dang dude dont know what to tell u, have u switched to different plugs and wires? thats what i did. the code is gone, try that, good luck bro and if u dont want homeboys LED tail lights ill give him my stockers for them lol. thanks dude good luck bro,

 

dude ive got 0 cash right now, like the couple hundred i had saved for mods is down to $30 lol. The last two weeks has been ******* **** on my savings... between the stupid dog eating gorilla glue, all the reptiles and the fiance ive blown like close to 2 grand!

You dont want the tails anymore? i thought you were hooked on them? ill take them i think they are sick as ****. Ill text you tomorrow and well work out sometime i can come out there or something

Im on NGK TR55s with MSDs. Ill pry go relocation kit soon and ill clear the code and re scan it after i switch everything. Glad you got your problems ironed out.

 

thanks good luck to you bro

 

danny disconnecting the battery with the engine running is a big no no...it only takes like 22 volts to fry a pcm or other computer in the car..and the alternator itself can have spikes greater then 22volts if there is no battery in the loop. as far as ur code and the gen l terminal... Gen L terminal for GM is the circuit that turns on and off the alternator when needbe. it sends a source voltage signal from the pcm to the back of the alternator to the stator windings to fire up the alternator...thus a check in that circuit would be ur first start..go down to the alternator and theres only one small wire in a connector on the back...and trace that wire...or u can power down and isolate the circuit and disconnect the pcm connector and check resistance from the wire at the alt to the wire at the pcm if u have a dmm...or u can check for a voltage drop in the wire...its solely up to u how to test...p1637 seems to be very popular in our cars. hope this helps

 

Thanks my white bro. actually the code is gone, thank god, ill never do that alternator test again, thanks dude. PM sent though!

 

Its most probably the excitor wire on the alternator. Its the only other wire going into the alternator besides the positive feed, it has a little connector at the end of it and the wire tends to get pulled out of the connector. They commonly break when removing the alternator, and it will throw that code. Good luck