[THRUST]

My Z has 1100 hundred miles and I have seen
this fault twice recently. It clears a second or two after the engine fires. The
voltage gage and DIC indicate 14 volts +/-
0.4 volts depending on system load. I've
never had any malfunctions while driving the
car, just this one occasionally when the car is started after sitting for several hours. I ran On Board Diagnostics and found 1 code (60-IPC U1064 H).
A little research defines this as a Body
Control Module comm error which is a (H)istory code. I'm thinking it may be the
result of the temporary fault at start up. The manual says this can happen if power is
inadequate to the module while the network is
listening for controllers that are online.
Everything works and the car runs great. It
is an odd thing that seems to be intermittent
and clears almost immediately. Anyone have
any experience with this? I've checked the electrical connections at the battery and alternator and they are in order. Thanks in advance for your help. I really enjoy this forum!

 

[CP]

Wow!! How'd ya put 110,000 miles on your Z already???? LOL

 

[Zippy]

Sorry can't help you with your question, but wanted to give you a warm welcome to the forum!!!

Zippy /phpBB/images/smiles/icon_smile.gif /phpBB/images/smiles/icon_smile.gif

 

[c4c5specialist]

HI there,
Your 1064 is a normal condition, as the communication codes, 1096, 1064, 1016 are considered a normal condition, which you may find in the future.
As for the voltage issue, you sound pretty handy, check for your voltage BEFORE you start the car, as if it is boarderline 12 volts, this message could show itself, as when the started is engaged, it will drop below 11.5, and flagg the message.
Personally, what I would do is to have the battery tested at your local dealer, just to be sure, and then proceed. Extended storage will enhance this condition.
Let us know how you do, and a warm welcome to you, c4c5

 

[IMA Z06]

thrust,
Welcome aboard, I think "c4c5" is right on with this one......

 

[THRUST]

Thanks everyone for the warm welcome and advise. Here is an update.

I attached a Fluke DVM to the battery and
then turned the key on to read the system
voltage indicated by the DIC. The DIC indicates 11.8 volts and the Fluke 12.2.
Started the car and no Fault reported
(figures cause I was ready for it). Voltage
gradually sweeps up to 14.8 (Fluke). I noted
that the Fluke at the battery terminals
consistently indicated 0.3 to 0.4 volts higher than the DIC. This does not concern me but I think it is good data for future reference. At the instant of startup the
voltage appeared to drop to approx. 11 volts (I need to do a few more trials to be sure).
I will have to activate the hold feature on the DVM now that I think of it.

One thing I did notice is that it seems the
the PCM delays the triggering to the alternator until it senses engine start. From my manual research this seems to be
consistent with how the system should operate. Thinking back to when the DIC
displays the fault, the PCM may have been a
little slow to trigger the alternator.
I'll keep you posted as I learn more but I
haven't seen the fault for a while now.

 

[mgarfias]

I've had mine do that a few times late last year. Each time it was after not driving it for awhile. It cleared itself after a second or so, and hasn't come back on in awhile.

Actually, I think it all happened with less than 5k miles on it. As long as its going away, I wouldn't worry about it.

 

[c4c5specialist]

Hi there,
Okay, so there is the problem.
Remember that the DIC does not read the actual voltage, it reads an input signal, not the actual volts, so you program the DIC with the correct voltage.
That is called a DIC recalibration, and should be done by your dealer with no further issue.
Best to ya, c4c5

 

[THRUST]

Thanks Doc!

Knowing its just a recalibration is a relief. I was concerned it may be some strange electrical gremlin. Thanks to this forum this discussion will likely benefit others.

My only other question is:
Can I initiate the recalibration myself or
is a Tech2 necessary?

 

[c4c5specialist]

Sorry thrust,
the Tech2 is needed to perform this function.
Best to ya, c4c5

 

[THRUST]

Dear Vette_Doc:

Spoke with a Covette Tech at my dealer
today. He was unfamiliar with a Tech2
menu option that performs a DIC recalibration. Can you describe how/where this is recal option is in Tech2 system?
Thanks for your assistance.

 

[c4c5specialist]

Hi there,
First, he has to input 98, NOT 01, then got through the car options, giving the hardtop, y body, then, he has to go to BODY options, once there, he must go to IPC, then special functions, then to IPC recalibration.
It will ask to have a Fluke attached, to give the reading, and then you input the correct reading, then he will hit save to hold the calibration.
Remember, you have a tolerance of .1, and if he has the DIC on the volts display, you will see it change right before your eyes.
Let me know how you do, c4c5

 

[Al_Cruz]

This is an old thread, but my car is only a couple of weeks old.

I have seen this condition a couple of times on my 02.

I guess the good news is it not a big deal.

Will write myself a note for when I do take it in for service.