High Voltage Warning

[Bob Voshell]

High Voltage Warning!

My 2001 Corvette Convertible has a problem that appears at times. The voltage gauge and the digital voltage display will show between 16 and 17 volts, the display will show HIGH VOLTAGE at that time and shut the dash down.
At the same time I check the alternator with a fluke meter and it is showing between 13.5 – 14.5 volt reading and does not change when the dash comes back. I also placed a SnapOn unit I have in the ADL connector and the voltage shows 13.2 – 13.5 at the most.
Bob

[c4c5specialist]

HI there,
You will need to recalibrate the DIC for voltage readings.

This is done with a Tech 2.

Allthebest, c4c5

[Bob Voshell]

Got your message about recalibrating the dash. I can understand that if it did it all the time but it doesn't always do it. It may go up when I first start it but then a couple of minutes into it will show the right voltage to match the fluke. Since it does it only at times do you still think it is a calibration issue?

[c4c5specialist]

Thank you for the additional information, that helps us help YOU!

That being said, you will have to check your engine ground sources, along with battery terminal torqued to 11 ft lbs.
Allthebest, c4c5

[Bob Voshell]

Good Morning! after further evaluation of the voltage problem it has come to my attention that when I first turn the key on the gauge and DIC voltage reading only comes down to around 13.5 to 14.5 while the fluke meter on the battery is reading approximately 11-8 volts. If I hit the key and start the motor at that point is when the dash flashes HIGH VOLTAGE and shuts off. If I leave the key on (motor off) for say 1-2 minutes the gauge slowly comes down to match the fluke. If I start it at that point the gauge works fine.
I am at present going to get a Tech 1 for this weekend and try the recalibration that you suggested. Thanks for the help. I'll let you know how I made out.

Bob

[ToolGuy]

Hey Bob, you need a Tech 2, not the Tech 1.

And do you have the DIC battery cal procedure?

[Bob Voshell]

Opps I menat Tech 2. I belive the procedure is in the manual isn't it?

Thanks

Bob

[Bob Voshell]

OK I thought I had the DIC calibration procedures but I couldn't find the item in the tech2 scanner. I did a sweep test several times but that didn't help. As soon as I starting driving it the message came up HIGH VOLTAGE and shut the dash down. I've checked again that the actual voltage out of the altenator was not the same as the IDC reading.

I tried to add the flow chart from the GM service manual that I have the CD's for and it says if there is more than .5v difference to replace the IPC?

Anyone have and ideas?

[ToolGuy]

Hey Bob, here is the procedure. Not sure if it is in the serv manual but someone posted here it was in body, so I took my Tech II and got to it. Here it is...


You measure voltage from the battery, engine on, accessories off.

Using the tech II, go under your cars year, body, than instrument panel.

You enter the voltage you got with the volt meter. Hit save.

That voltage then appears on your DIC, under voltage of course. The car uses what you programmed in as the voltage to calculate/read from.

[Bob Voshell]

Thanks for the update I'll give it a try. Just to confirm you check the voltage right at the battery terminals not what it says in the tech II in one of the three voltage sources? I know one was IGNITION INPUT 1 can't remember what the other two were but they all seemed to be a little different.

Bob