iambigperm

Anywhere from 1-5 minutes after starting my 2006 V the battery light and the "battery not charging" message is displayed. From the moment it is started the voltage is 14v at the battery, 14v on the scan tool and 14v on the display. This car has never had a low battery and never needed jumped. Everything works fine but I'm damn tired of pushing "ok" to acknowledge the damn message! I heard grounds can cause strange issues so I ran a redundant ground from the engine to the battery and it made no difference. Any ideas?

heavymetals

iTrader: (3)

Clean the battery ground below the hood strut and add a star washer.

iambigperm

I gave that a shot and it didn't help. It was a poor connection, but cleaning and the star washer didn't help. I was sure it would do it!

RADEoN

iTrader: (12)

The battery is 6+ years old... Time to replace.

07CTS-V

iTrader: (6)

The connection at the alternator has corroded inside. You can buy a new connector and extend the length so it's easier to work on or try to repair the current one by replacing the internal metal connectors.

You probably have a code for "alternator 'L' connection" or something along those lines.

iambigperm

I replaced the alternator plug today and if anything the light comes on faster. I replaced as much of the original wiring as possible without pulling the power steering pump out of the way. I'm pretty sure the break is right where the wires come out of the main harness. Now the message repeatedly comes on 15 seconds after starting. Before it was more random and could go several minutes.

I must have disturbed it more by replacing the connector. I'm doing a crank pulley on it this weekend so I'll try again at that point.

iambigperm

Started it this morning and it took 8 minutes for the light to come on. I don't know wtf is going on. I think ill check the actual signal at the ECM from the alternator and go from there.

RADEoN

iTrader: (12)

Again, my guess is a slowly dying battery.

iambigperm

The battery isn't original and load tests fine. I would buy another battery in a second if I thought that would do it.

RADEoN

iTrader: (12)

buy it and if it's not the case take it back

sod

iTrader: (1)

I'm getting a "Service Vehicle Soon" about 5 minutes after I've started mine. When I scan it, it's coming back as P1637C Generator L Terminal Circuit.
I occasionally also see the "Battery Not Charging" message as well.

I attempted to clean up the connector to the alternator, but when I pulled it apart, it looked perfect. (attached) I hit it with some contact cleaner & put it back together, but no dice. I cleaned up the ground near the hood strut & added a star washer as well. I'm still getting the message.

I also tested the red (orange? 15) wire with a multimeter & was getting 2.6 volts or so with the ignition 'on', no voltage with the ignition 'off' & no continuity to ground. Since I had pulled out the airbox to access the connector I didn't check the voltage with the car running.

I found this on ls2.com & it states there should be 10v at that when when the engine is running, but I'm not sure which vehicles this applies to.
http://www.ls2.com/boggs/dtcs/DTC%20P1637.htm

Does the FSM have a flowchart on troubleshooting P1637C?

If anyone has any further insight into this issue, please share.

Thanks!

TGIF!

heavymetals

iTrader: (3)

Those connections look horrible from the pics.

Depending on the miles, maybe the alternator brushes are going kaput.

iambigperm

I am going to fix this battery light if it kills me. I've tried several things since the last post.

1) checked wires further back into harness where alternator connector comes out-ok

2) Had Autozone and O-reilly test the alternator (on car) pass at both. Battery perfect as well.

3) checked resistance from PCM to alternator connector(both wires) -perfect.

4) Monitored alternator field wire at PCM. Voltage between 3-5 volts with everything on at idle. "Battery not charging" message will come on regardless of reading on this wire. From what the service manual says this wire is what the PCM monitors to determine charging system condition and set the charge light.

5) Just for kicks I ran the car with the battery charger hooked up on the medium setting. The light still comes on just as fast.

6) Tried the battery out of my Buick - same thing.

I am almost certain that the failure is heat related. First thing in the morning I can drive up to 10 minutes before the light comes on. Once it has come on I can turn the car off, restart it and it will come on almost immediately.

Could it just be the PCM itself? I am fairly certain there is no problem with the alternator. Ideas anyone?

Could the charging system monitor function be programmed out of the pcm?

The little crap like this just eats at me until I get it handled.

cwalker2006

iTrader: (11)

I have the same problem and it bugs the heck out if me too! I've only had the car for a few weeks and its driving me insane. If you come up with a solution definately let me know!

iambigperm

One thing I forgot to add... I also pulled all the grounds off the back of the cylinder heads and cleaned them. I'm hoping someone has some words of wisdom here because short of throwing parts at it, I'm out of ideas.

tommycompton

iTrader: (1)

Ive had this problem for 3 yrs now lol. I just ignore it, hoping it will go away.

I've had it on an old and brand new battery,I have an extra ground at the battery, I have even respliced the connecter. Car runs when you disconnect the battery, battery voltage is always fine and obviously charging, and same thing on two different ecm's. When i go in for my next tune I'm just getting the code turned off, permanently.
reading up on the subject it appears guys over in the vette foum experience simmilar issues. Some blame it on ecm tunes, aftermarket sparkplug wires or from using different than oem sparkplugs. I have all of the above, but I have switched back from aftermarket wires to stockers for awhile and still the light comes on. I have switched sparkplug, the light still comes on.
If your voltage is reading within normal parameters on the dic I wouldn't sweat it.

sod

iTrader: (1)

I double-checked & re-cleaned my connections this weekend & still no dice.

I'm seeing over 10v on the orange wire from PCM to ground. (10.65 ignition on & 10.35 engine running) (in a previous post I reported seeing 2.6v, but I found a better ground & now have an accurate reading)

I'm seeing no voltage from the gray wire to ground.

I've got continuity on the orange wire from PCM to Alt.

As for the issue being heat related, I'd bet that a condition of the code is that the coolant temp needs to be at a certain value. That would explain why the code takes several minutes to set the first time & then lights up immediately after starting when warm. Mine acts the same way.

BTW, I rarely see the "Battery Not Charging" message, typically I get "Service Vehicle Soon" which when scanned shows up as code P1637C 'Generator L Terminal Circuit'

I did get the "Battery Not Charging" obviously when I had the car running with the Alt unplugged.

FYI, mine's been coming on for over a year. I finally got around to looking into it...I think I'm going to go back to simply ignoring it...I'm out of ideas.

iambigperm

I used my buddy's snap-on scanner and it showed a P0621 when my generic scan tool was showing no codes somehow. My HP Tuners came in today and I disabled that code then thoroughly drove the car. No more light or message so far! That alone is worth the $600.

cwalker2006

iTrader: (11)

after i replaced my lifters thw other day i rarely get the message anymore. ive gotten it maybe teice this week instead of every 5 minutes. Imnot sure what i did but im gad i did it.

RADEoN

iTrader: (12)

grounds on the back of the heads came off, maybe that has something to do with it.