Check electrical system message?
 

Is anyone familiar with what might trigger a 'check electrical system' message on my 2006 ZO6 DIC?

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

Still working on this. I took it back from the shop and working through it each day.
The message "service electrical system" came on when i had new oem fuel pump, an alky control kit and dyno tune done, this was in the parking lot of the shop when I picked it up but the message was not there when I dropped it off.

The shop is either too busy or doesnt think Im a priority. They had the car for several weeks
Maybe change a part, then a week went by...before the car was charging it just steuggled at idle but it didnt have the "service elect system" message. They say they spent allot of time on it but think their work is infallable and wont check it to see if the items they added are causing some issue.
Also, there is one message for charging system and one for electrical system. Id like to know what part of electrical system it monitors or maybe all. I have the "service electrical system" not the charging system message.

A new alternator didnt change anything so the mechman 240amp went back on
They tried a new ecm too but were clear to tell me they doubted it would work...just an experiment and it changed nothing.

Got the car home by tow truck and when I first started the car I got healthy 14.7 volts and no messages. This might be the startup charging command, then i read that there are several factors that determine charge rate and different charging parameters.
After running....
A few minutes later, (A/C makes the problem more pronounced) the voltage drops, the car begins to stumble and this is before it is even hot. Once fans kick on its all over.

Something not commanding the alternator to charge or something in the recently installed upgrades or both.

Im wondering if the oem fans had something to send feedback to computer when they came on and kicked up voltage since there was a large unit to control the oem fan and the D3 is simply providing a solid state relay as their "pwm unit"

I cant see anything wrong with fuel pump connects at the tank but its hard to see.

When they installed the new fuel pump I noticed that pressure was actually a bit lower at idle, that pressure fluctuates a bit where I dont recall it doing that before.

I can see the fuel pump relay and the one next to it....numbers 35 and 55 are toasted looking (see pic)
If the connection is bad or some grounding then the voltage booster increasing voltage through might exaserbate the issue but not at idle.

Im going to look at instructions for ecs boost a pump installation to see if i can find an issue or mistake. The ground seems good.
Id liked for them to have used one of those beefed up fuel pump harnesses but i think it is too hard to retrofit at this point.

Knowing the components that signal the bcm such as the L terminal on the alternator and the path the electricity takes would be helpful if anyone has suggestion.

Anyone have similar issue after new fuel pump, alky, pump booster and dyno tune?

New plugs and wires changed nothing as I know some people had this experience.
Battery brand new.


https://cimg2.ibsrv.net/gimg/www.cor...ca8213a22d.jpg

https://cimg3.ibsrv.net/gimg/www.cor...6c225f7441.jpg

What plugs are you running now?

Found a chafed wire against the coil bracket, im going step by step with factory manual.
. When the car is charging or not, the L terminal circuit says "incomplete" with tech 2.
should it read something else?

NGK irridium tr7 ix i believe

Voltage was all over the place on mine with those too. Went to factory AC delco zr1 plugs and problem gone. I have logs before and after on the same day with that being the only change. It was bizarre.

Anyways, may or may not be your issue but that's my experience.

Try putting in a zr1 plug and see if it goes away. Could be simple EMI and plugs can fix that. Idealy you could move/shield/etc and fix whatever borderline issue that the plugs highlight, but most of the time it is just easier to change the plugs and be done instead of spending weeks testing/moving/etc.

Thought I found issue but the only thing Im not sure of is if the alternator L circuit is supposed to be complete or incomplete. Same with ignition relay circuit both on tech 2.

I test the L terminal and it was reading 5v and the car began to charge.

About 7 minutes into ths the charging subsides. The L terminal signal was 100% and F terminal signal was fluctuating as it should I suppose.

Then....i wiggled the plug for the alternator...charging came back slightly.
I pulled it off and re clipped the terminal to alternator, it began to charge...i wiggled the connector then I got both "service electrical system"
AND "service charging system"!
The voltage went up to 15.9v and stayed there. Seems the alternator became hot but not sure. WTH.
The connector looks ok but ill take it apart in morning.
So hard to figure this out!

Maybe as start if anyone can let me know if the L terminal circuit should read incomplete all the time or not.

The shop replaced the alternator and tried a new ecm as well but replaced with originals when the repair didnt work.
T




i

It cant hurt to try at this point as you and Unreal mentioned too.
At least it will be one thing eliminated.

Any resolution to this? Having the same issue.

+1 any solution to this? Was it the clip to the alternator?

Perhaps....