service charging system
 

Does any1 know how do I get this message to turn off without going to dealer?

Could probably tune it out/off, Bob.
Know *why* it's triggering a SCS?
Any codes? :confused2:

Can't tune it out.

Need to fix the issue. Could be bad alternator, plugs, wires, bad ground, bad battery, bad start solenoid or any number of items. Start with the easy checks and go from there.

TR6/7 plugs have a habit of setting that warning.

I've ran tr6/7 plugs in TONS of cars, and TONS of miles, never had it unless something else is compromising the system. They may highlight a poor charging system, but they do not cause the issue. Almost all of the ones that get it have a corroded ground, or bad starter solenoid, but people blame it on the plugs, when all the plugs are doing is highlighting they have an issue. With a proper operating system, they will not get the error.

They did in my case (and others too). Just shifted back to OEM plugs and the warnings went away. 100K miles on my alternator and never a hint of a problem.

https://www.corvetteforum.com/forums...ark-plugs.html

https://www.corvetteforum.com/forums...al-system.html

https://www.corvetteforum.com/forums...m-problem.html

https://www.corvetteforum.com/forums...ng-system.html

https://www.corvetteforum.com/forums...h-boost-3.html

Need I go on? You seem to have a habit that if it didn't affect you then it can't be an issue with anyone else.

Did you read what he said about the plugs being the straw that broke the camel's back? Too many links for me to read through all of it. BTW, he also listed plugs as one of the culprits in his first post. :cheers:

I'm also running TR6 with no issues.

Like I said, they can highlight a weakness in your electrical system, but do not cause the issue. Yes going back to OEM plugs will "fix" it, or you can find out what the weakness is and fix that.

Every single car with TR plugs that I've seen with a SES has been able to resolve it without swapping back to different plugs. Its amazing how many have melted starter connections or solenoids, and then putting the plugs in highlights that.

Reason I listed plugs was because a cracked/damaged, or improperly installed plug can cause it. If you read NGKs instructions, it specifically says do not use antisieze and the plug needs to ground through the case, and has a coating. Excessive antisieze does not conduct well enough and can lead to SES. If you used antisieze on the plugs, I would pull them out, clean them up, or put new ones in. Seen that cause SES too.

Service Charging System Message on DIC and DTC P0621

Models: 2005-2008 Chevrolet Corvette

2004-2008 XLR and XLR-V Series

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This PI was superceded to add information about aftermarket spark plugs. Please discard PIC4536A.

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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 that the Service Charging System message displays on the DIC. Using the Tech2, DTC P0621 is stored. This may be a result of aftermarket spark plugs or an open in circuit number 2540.

Recommendation/Instructions:
1. Check for aftermarket spark plugs. Plugs that are designed with a "Pulse" technology may interfere with this circuit and cause the Service Charging System message to illuminate on the IP and/or P0621 DTC store in the ECM. If aftermarket plugs are installed, replace plugs with OEM parts. This is not considered a warranty repair and all cost associated with this repair will be the customers responsibility.

2. Circuit 2540 is supplied voltage from the Horn fuse, position #2 in the UBEC. Apply the horn to see if it works. If the horn does not work, suspect an open fuse. This fuse may open if the horn is shorted due to water intrusion. If the horn is functional, check the integrity of circuit 2540 between the UBEC and the generator. Refer to SI document 1481125 for the schematic. Repair circuit 2540 as needed and re-evaluate the customers concern.


DTC Descriptor
DTC P0621: Generator L-Terminal Circuit


Diagnostic Fault Information
Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance

Generator Turn ON Signal
P0621
P0621
P0621
P0621


Circuit/System Description
The engine control module (ECM) uses the generator turn on signal circuit to control the load of the generator on the engine. A high side driver in the ECM applies a voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF. The ECM monitors the state of the generator turn on signal circuit. The ECM should detect low voltage on generator turn on signal circuit when the ignition is ON and the engine is OFF, or when the charging system malfunctions. With the engine running, the ECM should detect high voltage on the generator turn on signal circuit. The ECM performs Ignition ON and RUN tests to determine the status of the generator turn on signal circuit.

Conditions for Running the DTC
Ignition ON Test
• No generator, crankshaft position (CKP) sensors, or camshaft position (CMP) sensor DTCs are set.

• The ignition is in RUN position.

• The engine is not running.

Run Test
• No generator, CKP sensors, CMP sensor DTCs are set.

• The engine is running.

Conditions for Setting the DTC
• During the Ignition ON test, the ECM detects high voltage on the generator turn on signal circuit for 5 seconds.

• During the RUN test, the ECM detects low voltage on the generator turn on signal circuit for 15 seconds.

Action Taken When the DTC Sets
• The ECM will command the charge indicator and or warning message to be illuminated on the instrument panel cluster (IPC) and the driver information center (DIC), if equipped.

• The ECM will not illuminate the malfunction indicator lamp (MIL).

• The ECM will store conditions, which were present when the DTC set as Failure Records data only.

Conditions for Clearing the DTC
• The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

• Using the scan tool Clear DTC Information function can clear the DTC.

Diagnostic Aids
On vehicles equipped with a sense circuit connected to the voltage regulator.This circuit must have voltage for the charging system to operate properly.This circuit is used as a reference to control system voltage. All circuits must be tested at the generator before replacing any components.

I'm not seeing where a TR6 or TR7 implements any "pulse" technology as mentioned in the TSB.

They're not going to name specific aftermarket plugs in a TSB. If you'd have taken the time to read the other links it was/is a wide spread problem, hence the TSB. I simply mentioned this as a "possible" cause for the charging system warning. The intent of the post was/is not to debate this as the problem. I'm not wasting any more time arguing this. It's like wrestling with a pig.

There isn't even an argument though. We all agree, yes plugs can cause it.

My only thing was tr6/7 or BPR7/8 can be run if the rest of the system is working at 100% and they are installed properly.

Stock plugs can have the issue too, or aftermarket. Just stock plugs are far less sensitive to it.

To echo one of the items in the TSB, I've had a blown horn fuse cause that. Also a failing alternator.

thanks guys...naturally a couple day before trading in, this chyt pops up..

Nick, I keep getting this message but the car runs fine and doesn't have any charging issues. My alt is about 2 years old. I can leave it sitting for over 2 weeks without a tender and it starts with no issues. CPR replaced the battery last August after it sat for about 2 months. I did start noticing this warning come on after I swapped to TR6 plugs. Wires are 6 months old. My horn works fine and I couldn't find a burnt fuse in my box. So that leaves a dirty ground. I've never even looked for it, where is it located so I can take a look at it?

I've had this issue for over a year now but since it comes on and goes away within seconds and there's no other issues, I've just dismissed it.

Check starter solenoid first. Most common from what I've found. The headers bake the solenoid and ground there.

If all is good, it doesn't really effect anything, but start going down the list. Make sure battery terminals are clean/clear. Check all the grounds for corrision. Check the alternator lug and main power lug by fuse box to make sure they are tight.

Make sure someone didn't slap antisieze all over the plugs too.

Well, that's what you get for jumping ship! What's up with that??? Getting another one of those damned Vipers? ;)

Mine was a bad alternator.

I think Vipers are liked in this section....you can actually say it without hurting anyones feelings here...:lol:

:lol: Vipers are liked by folks who aren't butthurt. :thumbs:

Good luck getting your situation sorted out. :cheers: