Service Charging System
Thread Starter
Safety Car
Joined: Sep 2007
Posts: 3,902
Likes: 2
From: RIP Lotus
St. Jude Donor '09
Service Charging System
I had a cam with a 230s duration and 590s lift with a 112LSA installed in my 05 C6. When I am idling at a light, I see my foltage vary between 13.6 and 11.7 and inbetween. I have no issues with the car running or running my accessories when idling. I think the computer sees the change in voltage as a problem and reports it to me every time I idle the car.
This is no doubt due to the rougher idle from the cam.
My question for you all is can I turn of the ding and also even the message through the ECU. The message doesn't really bother me but the ding is horrible.
Also, what can I do to the engine to make this message stop comming up?
This is no doubt due to the rougher idle from the cam.
My question for you all is can I turn of the ding and also even the message through the ECU. The message doesn't really bother me but the ding is horrible.
Also, what can I do to the engine to make this message stop comming up?
Thread Starter
Safety Car
Joined: Sep 2007
Posts: 3,902
Likes: 2
From: RIP Lotus
St. Jude Donor '09
Crank pulley is 25% underdriven but the warning doesn't come up at a certain low voltage, it comes up at any given voltage but I think it is because of the amount of change.
Does anyone know what the sensor uses to decide to alert the driver?
Does anyone know what the sensor uses to decide to alert the driver?
Last edited by NavyC4S; Dec 29, 2007 at 02:52 PM.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
I've seen this a couple of times, usually after first starting the car. Pay attention to the volt meter when starting, if it doesn't go up to 14 right away give it a little rev up until the volts go up. I read the alternator needs to be "energized" to start producing voltage.
Instructor
Joined: Feb 2007
Posts: 106
Likes: 0
From: Henderson Nevada
error code
Soon after Chuck coW super tuned my ride, we noticed that I was throwing a charging code, we only experinced this while traveling at warp speed, at ideal my volt meter would vary between 13.0 to 14.2( so the alternator was working just fine), go figure anyways everything to this day runs top notch, and Chuck just worked his voo doo and made my faulty code disapear in thin air, if my voltage drops below 10 amps when charging I would surely suspect and issue with my alternator.
Melting Slicks
Joined: Jun 2002
Posts: 2,168
Likes: 16
From: Phoenix AZ
Mine did this shortly after LG did a H/C w/ U/D pulley package on my car. It turned out to be nothing to do with the cam or pulley it was the alternator. After I replaced it the problem went away. From what I have read here a few months ago there is a GM bulletin for this.
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Former Vendor
Joined: Nov 2005
Posts: 11,792
Likes: 255
From: Ossining New York
St. Jude Donor '07-'08-'09-'10-'12-'13-'14
Call me and I'll help you out....
I had a cam with a 230s duration and 590s lift with a 112LSA installed in my 05 C6. When I am idling at a light, I see my foltage vary between 13.6 and 11.7 and inbetween. I have no issues with the car running or running my accessories when idling. I think the computer sees the change in voltage as a problem and reports it to me every time I idle the car.
This is no doubt due to the rougher idle from the cam.
My question for you all is can I turn of the ding and also even the message through the ECU. The message doesn't really bother me but the ding is horrible.
Also, what can I do to the engine to make this message stop comming up?
This is no doubt due to the rougher idle from the cam.
My question for you all is can I turn of the ding and also even the message through the ECU. The message doesn't really bother me but the ding is horrible.
Also, what can I do to the engine to make this message stop comming up?
Call me and I'll help you out.... I've seen this before....
Chuck CoW
Thread Starter
Safety Car
Joined: Sep 2007
Posts: 3,902
Likes: 2
From: RIP Lotus
St. Jude Donor '09
I took the car to the dealer and had them install a new alternator. At first, the message did not appear when the car idled. I did notice that the battery voltage rarely went above 14.0v when the old alternator had it at 14.6v at startup.
The message eventually came back, but not as often as it did with the previous alternator. The Voltage still won't go higher than the low 14s and when idling, it will slowly drop to around 12 and level out.
This leads me to believe that due to the UD pulley, the alternator is not spinning fast enough at idle. I will be putting a smaller pulley on in early next week and I will let you all know how it goes.
Any other suggestions?
The message eventually came back, but not as often as it did with the previous alternator. The Voltage still won't go higher than the low 14s and when idling, it will slowly drop to around 12 and level out.
This leads me to believe that due to the UD pulley, the alternator is not spinning fast enough at idle. I will be putting a smaller pulley on in early next week and I will let you all know how it goes.
Any other suggestions?
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
What is your idle set at?
Do you notice your fan kicking on and off causing it? Or any other heavy electrical draw kicking on or off?
I have mine at 750 with an underdrive pulley and I noticed that mine only does it at start up (and rarely at that) which is not the problem you are having.
Do you notice your fan kicking on and off causing it? Or any other heavy electrical draw kicking on or off?
I have mine at 750 with an underdrive pulley and I noticed that mine only does it at start up (and rarely at that) which is not the problem you are having.
Last edited by Joe_G; Jan 4, 2008 at 10:27 PM.
Advanced
Joined: Nov 2006
Posts: 89
Likes: 0
From: Tampa FL
Did you change the sparkplug wires? I have all the mods you have and didn't have the problem until I changed the stock wires out for unshielded MSD wires. I found a post on here from about 2 years ago of people having the same problem and changing back to shielded wires fixed the problem for them also. It is electrical interference between the front wire and the alternator that triggers the Service Charging System message.
Thread Starter
Safety Car
Joined: Sep 2007
Posts: 3,902
Likes: 2
From: RIP Lotus
St. Jude Donor '09
What is your idle set at?
Do you notice your fan kicking on and off causing it? Or any other heavy electrical draw kicking on or off?
I have mine at 750 with an underdrive pulley and I noticed that mine only does it at start up (and rarely at that) which is not the problem you are having.
Do you notice your fan kicking on and off causing it? Or any other heavy electrical draw kicking on or off?
I have mine at 750 with an underdrive pulley and I noticed that mine only does it at start up (and rarely at that) which is not the problem you are having.
My fans are always on...That could be it, come to think of it.
I also did change the sparkplug wires to MSD for the cam install. Why would they only cause interference at idle?
I think the new alternator fixed the draining of the battery, but the fans do bring it down to 12ish on idle.
Drifting
Joined: Oct 2006
Posts: 1,608
Likes: 7
From: DELRAY BEACH FLORIDA
St. Jude Donor '10-'13
I had a cam with a 230s duration and 590s lift with a 112LSA installed in my 05 C6. When I am idling at a light, I see my foltage vary between 13.6 and 11.7 and inbetween. I have no issues with the car running or running my accessories when idling. I think the computer sees the change in voltage as a problem and reports it to me every time I idle the car.
This is no doubt due to the rougher idle from the cam.
My question for you all is can I turn of the ding and also even the message through the ECU. The message doesn't really bother me but the ding is horrible.
Also, what can I do to the engine to make this message stop comming up?
This is no doubt due to the rougher idle from the cam.
My question for you all is can I turn of the ding and also even the message through the ECU. The message doesn't really bother me but the ding is horrible.
Also, what can I do to the engine to make this message stop comming up?
Advanced
Joined: Nov 2006
Posts: 89
Likes: 0
From: Tampa FL
Idle is set at 900.
My fans are always on...That could be it, come to think of it.
I also did change the sparkplug wires to MSD for the cam install. Why would they only cause interference at idle?
I think the new alternator fixed the draining of the battery, but the fans do bring it down to 12ish on idle.
My fans are always on...That could be it, come to think of it.
I also did change the sparkplug wires to MSD for the cam install. Why would they only cause interference at idle?
I think the new alternator fixed the draining of the battery, but the fans do bring it down to 12ish on idle.
Thread Starter
Safety Car
Joined: Sep 2007
Posts: 3,902
Likes: 2
From: RIP Lotus
St. Jude Donor '09
Can I just replace the #1 wire with a stock shielded wire?
Or, do I have to replace all the wires?
What to do about the voltage dropping to 12 when idling SOMETIMES?
Is the alternator shorting to the plug wire?
Should I still overdrive the alternator?
And Finally, How much should I pay for a used FAST with the Map relocator? (OT, I know but since I have your attention)
Former Vendor
Joined: Nov 2005
Posts: 11,792
Likes: 255
From: Ossining New York
St. Jude Donor '07-'08-'09-'10-'12-'13-'14
Some 07 C6's......
I've seen a GM bulletin (and have had it happen to me) where you max throttle a C6 to redline and the fan inside the alternator moves outward and contacts the field windings and causes a short or the diode to fail which either kills the alternator or at a minimum turns on the L-Terminal code and check engine light.
I've seen it a few times.....
Chuck CoW
I've seen it a few times.....
Chuck CoW
Intermediate
Joined: Feb 2005
Posts: 25
Likes: 0
We just had the same issue with a set of Taylor wires. Ended up replacing the cylinder closest to the alternator back to a stock wire and it went away. Time to pick up some EMI shielding.