Replaced alternator, charge system fault
Thread Starter
Heel & Toe
Joined: Apr 2007
Posts: 21
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Replaced alternator, charge system fault
Hello all,
I have a Corvette C5, 2002, and I had an issue with my alternator which I had replaced with a brand new one. Everything seems fine except that I keep getting the error message: CHARGE SYSTEM FAULT and when I check my error codes I have this: P1638 - Generator F-Terminal Circuit.
Anyone know how I can get rid of this error message? I tried resetting the codes but it just comes back whenever I turn on the car.
I have a Corvette C5, 2002, and I had an issue with my alternator which I had replaced with a brand new one. Everything seems fine except that I keep getting the error message: CHARGE SYSTEM FAULT and when I check my error codes I have this: P1638 - Generator F-Terminal Circuit.
Anyone know how I can get rid of this error message? I tried resetting the codes but it just comes back whenever I turn on the car.
Thread Starter
Heel & Toe
Joined: Apr 2007
Posts: 21
Likes: 0
No, I think the service shop threw the old alternator away. In any case, it seems to be working fine as the battery is being charged and all electronics is working fine. It is just this pesky error message which wont go away.
Thread Starter
Heel & Toe
Joined: Apr 2007
Posts: 21
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Really no way to get rid of this message? Because there seems to be only one error code, 1638, which seems to indicate that the current is out of range of allowed boundaries.
Le Mans Master
Joined: Nov 2005
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Many have their OLD one rebuilt and keep the electronics. That's how!
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Thread Starter
Heel & Toe
Joined: Apr 2007
Posts: 21
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Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
Here is one discussion of the Valeo alternator.
http://forums.corvetteforum.com/c5-t...-98-coupe.html
or better yet:
http://forums.corvetteforum.com/c5-t...leo-style.html
Post #12 pertains to YOU!
http://forums.corvetteforum.com/c5-t...-98-coupe.html
or better yet:
http://forums.corvetteforum.com/c5-t...leo-style.html
Post #12 pertains to YOU!
Last edited by dougbfresh; Jun 6, 2012 at 12:41 PM.
Team Owner
Joined: May 2006
Posts: 21,473
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From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
However it appears that some things are different in some years!
In my buddies 2004 there is NO provision for the P1638 F Terminal only a P1637 L terminal-
But in my 1998 it has both the P1638 F Terminal Circuit and the P1637 L Terminal Circuit
It does appear that you should be able to access the PCM with tuning software and put it in a no report mode - Do this "ONLY" if you Charge System is in fact working!
I would think that for one reason or another the Alt you purchased was from a different year or manufacturer and is not jiving with the F Terminal that needs to be reported.
Thanks,Matt
Thread Starter
Heel & Toe
Joined: Apr 2007
Posts: 21
Likes: 0
By looking at my HP Tuners DTC chart - it does appear you can turn the function 'OFF' or to no report.
However it appears that some things are different in some years!
In my buddies 2004 there is NO provision for the P1638 F Terminal only a P1637 L terminal-
But in my 1998 it has both the P1638 F Terminal Circuit and the P1637 L Terminal Circuit
It does appear that you should be able to access the PCM with tuning software and put it in a no report mode - Do this "ONLY" if you Charge System is in fact working!
I would think that for one reason or another the Alt you purchased was from a different year or manufacturer and is not jiving with the F Terminal that needs to be reported.
Thanks,Matt
However it appears that some things are different in some years!
In my buddies 2004 there is NO provision for the P1638 F Terminal only a P1637 L terminal-
But in my 1998 it has both the P1638 F Terminal Circuit and the P1637 L Terminal Circuit
It does appear that you should be able to access the PCM with tuning software and put it in a no report mode - Do this "ONLY" if you Charge System is in fact working!
I would think that for one reason or another the Alt you purchased was from a different year or manufacturer and is not jiving with the F Terminal that needs to be reported.
Thanks,Matt
So most likely the reason for the issue is that the alternator is just outputting a different current than what the PCM is programmed to accept.
Anyway, are there any resources you can point me to which shows which is the best tuning software for this job and how to use it to connect to my vette?
Thanks,
Shawn
Team Owner
Joined: May 2006
Posts: 21,473
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From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Thanks for the response. The charging system seems to be working just fine as I have been using the car, daily, for two weeks and I have no indications about my battery being drained.
So most likely the reason for the issue is that the alternator is just outputting a different current than what the PCM is programmed to accept.
Anyway, are there any resources you can point me to which shows which is the best tuning software for this job and how to use it to connect to my vette?
Thanks,
Shawn
So most likely the reason for the issue is that the alternator is just outputting a different current than what the PCM is programmed to accept.
Anyway, are there any resources you can point me to which shows which is the best tuning software for this job and how to use it to connect to my vette?
Thanks,
Shawn
Your best bet is to hunt down a tuner that already has HP Tuner or as you stated LS1 Edit to turn off the code.
Otherwise you will need to purchase either of the two and do it yourself. It will be pretty pricey to do it this way. You could also speak with a tuner here in the states and send them your PCM as well -
BUT it may even be cheaper to purchase the correct or specific alternator.
Do you think the shop might still have it on hand? If so go grab it and take a picture of it and the one you have now.
Plus take a picture of the one you have now of the PART NUMBER on it, that'll help. Perhaps we can get you something.
Where did you purchase the Alt from?
Thanks,matt
Team Owner
Joined: May 2006
Posts: 21,473
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From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Are there any other numbers by chance?
It almost looks like the clip isn't plugged in all the way! Can you double check that?
Thanks,Matt
It almost looks like the clip isn't plugged in all the way! Can you double check that?
Thanks,Matt
Tech Contributor
Joined: Jan 2007
Posts: 19,470
Likes: 1,171
From: Dyer, IN
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Trip out though, in HP Tuners under the DTC's and how you can adjust them, there is "NONE" on the list for the 2004 that has the P1638 I cannot explain why but it just does not exist!
It does for other years
but not in the 2004's - neither in my buddies 2004 Z06 nor my other buddies 2004 Coupe -
Can anyone at all explain this to me? Huh can anyone? Huh?
Flippin crazy man, I tell yeah crazy! You say it is and yet it does not!
Someone explain!
Thanks,Matt
It does for other years
but not in the 2004's - neither in my buddies 2004 Z06 nor my other buddies 2004 Coupe - Can anyone at all explain this to me? Huh can anyone? Huh?
Flippin crazy man, I tell yeah crazy! You say it is and yet it does not!
Someone explain!Thanks,Matt
Tech Contributor
Joined: Jan 2007
Posts: 19,470
Likes: 1,171
From: Dyer, IN
Trip out though, in HP Tuners under the DTC's and how you can adjust them, there is "NONE" on the list for the 2004 that has the P1638 I cannot explain why but it just does not exist!
It does for other years but not in the 2004's - neither in my buddies 2004 Z06 nor my other buddies 2004 Coupe -
Can anyone at all explain this to me? Huh can anyone? Huh?
Flippin crazy man, I tell yeah crazy! You say it is and yet it does not! Someone explain!
Thanks,Matt
It does for other years
but not in the 2004's - neither in my buddies 2004 Z06 nor my other buddies 2004 Coupe - Can anyone at all explain this to me? Huh can anyone? Huh?
Flippin crazy man, I tell yeah crazy! You say it is and yet it does not!
Someone explain!Thanks,Matt