C4 on board electronic diagnostics.

[Ruby Rag Top]

Suggestions please. I have consulted the bibles from Haynes and Chilterns to no avail.
My 1993 convertible has just started intermitantly flashing one of the display bulbs on the centre dash . This seems to be on every occasion that you start the car, however, it stops after a short while and remains steady until the next time you restart the car.
The light in question is the one that displays which function of the climate control you are using. This started a couple of days ago and is the first time it has happened in nearly 4 years of ownership.
All appears to be working fine with everything on the car, but knowing how clever our Vette's can be at warning us of problems, I thought I'd ask if anyone knows if this is just an annoying occurence or the first sign of a problem.
Sorry for the length of this and thanks for any help.

[c4koh]

Do you mean the flashing light is on the DIC ("Driver Information Center" - the little black area)... or on the actual aircon control panel?

Either way, what I would do first is to shut down the car, and start it up... and COUNT the number of flashes... There may be a pause as well, so you may get two codes, e.g.

FLASH-FLASH-FLASH... little pause ... FLASH-FLASH-FLASH-FLASH

This may give a code "3-4" which we can look up in our factory service manual.

Worth a try for the first point of investigation. I have a service manual for a '91, am sure the '94 isn't too different...

[Ruby Rag Top]

It is the green light which indicates which function of the climate control you are using. I generally keep it in the auto setting. However, I have pushed a button to move it to another function whilst it flashes and the 'new' indicator light flashes at the same rate.
I will try to couny the number of times it flashes and let you know to see if it is of any significance.

Thanks for the quick reply. Going out now so won't be on the computer for a few hours.

[vetteheadracer]

Seem to remember C5RagTop had a similar problem with his C4. From memory it "flashes" to indicate a fault on the aircon system. You can clear the warning by holding the aircon button for 20 seconds I believe.
Maybe a warning that your aircon system needs recharging. When did you last have it charged up? If you are going to get it recharged, change the brushed aluminium cylinder thingy that sits behind the radiator. (Condensor?)

[c5ragtop]

I remember that too. I think there was there was something in the C4 owner's handbook about resetting the air con if it flashed.

In the end I got it recharged by another C4 owner who is an air con engineer and had some of the correct gas left. If you send me an e-mail Colin, I can let you have his contact details.




>> Edited by c5ragtop on Thursday 4th November 09:52

[shagga]

HAd a similar problem with my 95. As the refrigerant was low I had it refilled and not had the problem since. It will still be worth counting the flashes and we can check what the manual says. I have a 95 manual that i can look at tonight when I get home.

[Gixer]

Mine has been doing the same all summer. Its something I was going to sort this winter. The heat control unit has its own diag system. I will have to check how to get into it but its something like press both the hot & cold buttons at the same time. Or pos. the fan up and down. Once you get the code from the unit, look it up in the aircon section of the manual, chapter 2 from memory. Or goto ZR1.net and find it there.

[TEKWIZ]

If it needs recharging I have used a specialist AC man and he is mobile (he comes to you)and based in Sutton Surrey, I have spoken to him he can help; his details are; Kevin Jenkins, Southern Aircon: Tel: [phone] Mobile:[phone]

Good Luck

[c4koh]

Well, on the subject, I get no flashes on mine but the aircon isn't working - i.e. there's no cold air coming through...

I suspect this is just lack of refigerant, but I'll go through the diagnostics for this and see if that is the case at some point (then again maybe I won't be bothered!)

[sunnyZR1]

Ok, the light is flashing because you have a malfunction code stored in the AC head unit memory. To review the code you have to push simultaneously the up and down arrow buttons and hold them for 5 seconds, the display will show 00 , now you are in diagnostic mode, push the central button to review any codes stored (you will need a manual to read what every code mean, or write them on this forum and I will look them up for you).
Before doing anything else, I would try to unplug the battery for 60 seconds and pllug it again(or remove the AC fuse in the far passenger side of the dash if you do not want to lose you radio memory), this will reset the AC head unit logic software, and if it was just an intermitent electronic or software fault your AC will blow cold again, if it was a "real" fault (low on gas, bad clutch, etc) you will have to sort it out anyway.
Good luck
SunnyZR1

[Ruby Rag Top]

Thanks for all the replies. I willl now sift through the info and try the various suggestions. It would seem to point to the air-con, it would be nice if it was only a recharge.
This just goes to show what a bloody good bunch of blokes Vette owners are when it comes to helping each other. Thanks again. Colin

[vetteheadracer]

BTW Colin if it turns out to be serious i.e .a broken a/c clutch unit (big thingy on the belt that looks like another alternator) I have a brand new one that I bought for Velveteen when I thought mine had broke....turns out it hadn't!