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Weird DIC/idiot lights issue

C

charlzm

New member
Have had my GTP since it was new with 5 miles on the odometer; bought it in 1998. On to the problem...

Just before my GTP turned over 200,000 miles a few months ago, the DIC started blinking every reading all zeroes. The TCS light also came on steady in the DIC as did the ABS light on the dash.

They went away and everything was fine, but they started coming back after a few hundred more miles.

After 200,000, (not exactly at, by the weay) they started to come on more frequently and eventually to stay on.

Now, at 209,000, this is the routine: key in ignition results in ABS and TCS lights coming on, followed by the DIC displaying all zeroes in about five to ten seconds.

This is inconvenient as I can't use anything like fuel used, oil life range or vehicle range on the DIC any longer.

Yesterday, the fuel gauge plunged to the bottom, then came back up to 3/4 of a tank where it should have been. Today, the "low traction" light came on briefly as I was just cruising down the freeway.

BTW, I plugged in an OBDII reader yesterday and there are no codes.

Anyone seen anything like this before?
 


Sounds like an electrical issue to me. I would start with checking out the battery and the battery connections. Make sure they are clean and tight. Don't just look at them. Remove them, make sure they are not corroded, then install them onto the battery. Make sure they tighten up good and are making good connection.

I would start there. If that doesn't help, I would look into the ignition switch next.
 
Thanks for the advice, Zeff. Will check it out this weekend.

Oh, and to add a little more detail, the car isn't behaving as if the ABS or traction control is off.
 
I am subscribing to this thread because this is the same issue that I am having. The DIC goes to zeros, TCS light goes on and off, ABS light on and off, etc.

Have you discovered anything yet with your issue? I am going to check it over this weekend to see if any of Zef_66's suggestions work. But I have an ignition switch on the way. If I can't find anything then I am throwing that ignition switch in.
 
mainjet said:
I am subscribing to this thread because this is the same issue that I am having. The DIC goes to zeros, TCS light goes on and off, ABS light on and off, etc.

Have you discovered anything yet with your issue?
Click to expand...

Nope. Tried the battery thing; it didn't work. I'm guessing it has something to do with the computer sending bad info to the DIC and the warning lights, but I don't know where along the signal chain that would happen.

By the way, the DIC works for the first few seconds the car has started, but the blinking zeroes take over within ten seconds.

Also, the TCS / ABS lights, which had been on steadily, started blinking last night and today. When they did that, the DIC cleared and now functions properly.

:th_confused:
 
I doubt the pcm is sending bad info to those items. The car probably wouldn't run right if that were the case.

A pinched wire behind the dash is more likely. Say you put an aftermarket radio in. Maybe it's a bit longer than the stocker and a wire got pinched. That coudl ground out the dic and cause funky readings. Or a rubbed wire, loose connector to the dic.. stuff like that.

the fuel gauge sounds like the sender (common) is starting to go bad.
 


Charlzm - sounds like you and I have identical issues. so maybe we can work this together and post what we find out in order to help each other.
see my post
http://www.grandprixforums.net/sound-like-ignition-switch-you-53934.html

I have an ignition switch on the way so I think that I will throw that in anyway. Can't really hurt but I have been told that it probably isn't that.

Also, my HUD will go out by itself and then come back on. I have an extra switch so I am going to put that in to see if anything is going on there. While I am in there doing all of that I will trace all the wiring to the HUD, DIC and anywhere else I can think of to see if there are any wires chaffed.

BTW does your performance shift work at this point? mine seems to have gone out along with this issue.

Appearently the trip calculator does a self test and if it does not get the serial data that it wants within 10 seconds it flashes zeros. Here is a blurb from alldata
"The trip calculator performs an error detection when a serial data stream is not present for 10 seconds. If the trip calculator is not able to calculate a value, due to any missing data, the display shows a flashing 0 when the mode is selected. The trip calculator updates the display with the correct information for each mode that is selected within a given time frame."

Anyway, I will let you know if I find anything and you please do the same for me.
 
mainjet said:
Charlzm - sounds like you and I have identical issues. so maybe we can work this together and post what we find out in order to help each other.
see my post
http://www.grandprixforums.net/sound-like-ignition-switch-you-53934.html

Also, my HUD will go out by itself and then come back on...

BTW does your performance shift work at this point?

Appearently the trip calculator does a self test and if it does not get the serial data that it wants within 10 seconds it flashes zeros. Here is a blurb from alldata
"The trip calculator performs an error detection when a serial data stream is not present for 10 seconds. If the trip calculator is not able to calculate a value, due to any missing data, the display shows a flashing 0 when the mode is selected. The trip calculator updates the display with the correct information for each mode that is selected within a given time frame."

.
Click to expand...

Interesting...

My HUD has gotten very dim but still functions without issue. I can't see it in daylight hardly at all any more, but I still see it at night.

Performance shift is fine. As you may know, the indicator light for P.S. mode in 98's is on the dash (not the DIC) and it still functions properly.

Trip Calculator? I don't have one of those. The DIC in my 98 shows MPG, fuel used, oil life and range. For a brief few seconds at startup (before the zeroes take over, the info will display on the DIC correctly. It doesn't seem to be keeping up with the fuel-based items but the oil life is still ticking down at what seems like an appropriate rate.

I'm wondering if the fuel sender mentioned by BillBoost might be the culprit. Still, that wouldn't explain the TCS and ABS lights staying on steady and once in a while flashing. When they flash, the DIC starts working again.

I may just bend over and take the car to the GM dealer nearby for diagnosis. Will let you know what I find out if I do.
 
BillBoost37 said:
I doubt the pcm is sending bad info to those items. The car probably wouldn't run right if that were the case.

A pinched wire behind the dash is more likely. Say you put an aftermarket radio in. Maybe it's a bit longer than the stocker and a wire got pinched. That coudl ground out the dic and cause funky readings. Or a rubbed wire, loose connector to the dic.. stuff like that.

the fuel gauge sounds like the sender (common) is starting to go bad.
Click to expand...


Hmmm, haven't done anything to or with the dash wiring since the car was a week old. Could still be the culprit, but there's no obvious connection.

Fuel gauge sender is probably going, yes.
 
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