The NNIAL8R

on DIC...

2007 C6Z...7800 miles...
Battery tests fine...car starts and runs fine....lights are nice and bright...alternator putting out 14.5 volts...Always use a Battery Tender when not driving the car...Everything seems normal other than the constant "Check charging system" message....I also ran a code check with a OBDII and there are no codes....Car is out of warranty so dont want to take it to the dealer unless absolutely necessary...Anyone experience this before??

Gering

Do you have an under drive pulley?

The NNIAL8R

No, the car is 100% stock other than Corsas...

AreOhBeeC6Z

Had the same thing happen to me around 13k miles when I was stock on my 2006, ended up being my Alternator. See if you can find a local shop that would rebuild it for you, that would probably be your cheapest route.

peterpiper

I'll bet the alternator as well. I get the message when I use both cigarette lighter ports at the same time. I have about 36K in a 2007 C6Z. -pp

lgsdds

I had this happen to my 09 and it might be worth checking to see if your horn works. If it does, revert to all the preceeding suggestions. If it does not, there is a fuse in the engine compartment fuse block that services the horn and something called "alternator sense." That fixed mine. It is a long shot, but might be worth checking.

sdunn

That message displayed on my car also. I also noticed while heavy acceleration, the volts would drop. At idle or normal acceleration, it held the voltage at normal. I was at a shop and they swapped out my alternator with an extra one they had to test it. it held the voltage at all times and no more message. So now I have to buy the alternator.

BgBoost1

Agreed....Check the Alternator!

HyperX

This is common on the C6. You sure you didn't change plugs or wires? I had that too. I changed the battery - it went away for a while and came back. This was on a modded C6. On my Z06 I have not had it, but it's 100% stock.

cencalc6

Before you got the error, did you run the car hard?....I had a few hard pulls on the freeway and the same error appeared....I popped the hood open and heard a grinding noise at the alternator....I let the car cool down and it went back to normal...eventually I swapped out the alternator and since then I have not the error

The NNIAL8R

The car only has 7800 miles...I would hope the plugs and wires wouldnt already need changed...

The NNIAL8R

I dont drive the car hard at all...the alternator is quiet, no grinding or squealing...again, everything seems normal with the exception of the message I keep getting on the DIC...ALso, Ive driven the car with the DIC in the voltage mode...it never dips below 14.1 volts

The NNIAL8R

BINGO!!!!...The alt sense/horn fuse was blown...I replaced it, but it blew again the second I hit the horn....I replaced it again, took it for a drive (without using trying the horn)...No "service charging system message".....Now I just have to find the short in the horn

Thanks man...I was getting ready to shell out $$$ for an alternator!!

lgsdds

You are welcome. Glad the long shot worked out.

HyperX

When you change to non OEM wires and plugs you get this message. Tons of topics on C6 gen covering this topic. Mine started to do it after I changed wires and plugs. DMy C6 also had about 8000 miles when this started to happen. I had alternator tested and it was not it... This is especially prevalent at night, when you are running lights, right?

spicytuna

That's great!

In the meantime, you can attach this to your driver side door.

davidelowe

Most 2007s are still under factory powertrain warranty and the alternator falls under that umbrella. I work at a chevy dealership in sales and our service writers don't know alternators are still covered unless you tell them.

QwikC

However it may serve...

:: Service-charging-system-my-problem-and-resolution


Also...

Re: bad electrical failure (08 Z06)

There's a good chance it's the alternator. At high rpm the internal fan blades can come in contact with the windings, resulting in the signs you described.

Although the following TSB was issued for '07 cars, some '08 cars are experiencing this issue as well.

The fix is a new alternator. At the time the following TSB was issued, the new alternators had a different part number (15841234), although that may have since been superseded.

The difference being, the new units have a clutch which prevents the alternator from attaining excessive rpm and in turn resulting in the internal fan coming in contact with the windings. This was a fix for '08, but not all cars have them depending on build date.

Lastly, OnStar will not always be able to 'see' every code and may only be able to see codes that cause the CEL to illuminate.

Subject: Service Charging System P0621 DTC Stored - keywords alternator battery charge dic generator gauge light
low ls2 ls7 voltage #PIC4402A - (04/11/2007)

Models: 2007 Chevrolet Corvette

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This PI Supersedes To Include Looking For Short On Generator Bracket. Please Discard PIC4402.

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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Some customers may comment of a "Service Charging System", "Service Electrical System" and/or a "Battery Voltage Low" message on the DIC accompanied by DTC P0621 in the PCM. This may be the result of a shorted wire on the generator bracket or a cut in the stator winding that is caused from high engine RPM, usually because the engine hit the rev limiter. The internal fan is flexing and when it does flex, it comes into contact with the winding. A new generator may do the same thing if the engine is placed against the rev limiter.

Recommendation/Instructions:

Inspect circuit 225 for a short to ground on the generator support bracket, where indicated in the picture below. If no wire concerns are found, replace the generator with current SPO stock.

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MOSPORT1

is that so?? I have an 07 and just had mine replace under my GMPP with
$100 deductable.. Going to have to inquire about that! Thanks,,,

Blurr

Depends what deductible GMPP you went with. I just had my alternator replaced (kept getting the DIC message at high RPM), no deductible.