Ooglie Googlie

Hey everyone. Maybe someone can help. Recently bought a 2003 ZO6 with 19000 miles. Never owned a C5. Had it for a week. Two problems have risen.

Recently, the battery died. Jump started it with a battery charger. This must of damaged the ECM because now I have no traction control or ABS. Dash lights are on.

Therefore, would it be possible to install a cut off switch at the negative battery terminal temporally until the problem is fixed? I do not want to worry about jumping it again and damaging something else.

Also, I have removed the ECM and sent it out to ABSfixer. I have covered the block where the ECM mounts with plastic and covered the connector with plastic to protect it from debris.

Right now I am very upset so please be easy on me. The car is beautiful and runs so strong. I think it was an older man who owned it. Everything is so clean. Just want to do the right thing with the car.

Thanks.

BURL

Look under the stickies at the top of this thread. Start with
IMPORTANT ELECTRICAL INFORMATION (Long!) (Multi-page thread 1 2 3 ... Last Page)
Thread Rating: 6 votes, 5.00 average. Bill Curlee

Bill is a great resource for the phantom battery drain common on the C5. Search for his posts - I know he has one that goes step by step in solving this problem. Most people look over the drain unless it is extreme - I however feel is is a defect in the C5 and should have been fixed rather than ignored by GM. Every GM car I've had could be left for a minimum of 2-3 months and still crank - not my C5! Hope this helps with your issue.

laurent_zo6

Recently one person had a battery drain and found out that it was his glove compartment light that stayed on. Not the first thing you would think of.

Rob 02

It is more likely that you damaged the alternator than PCM by jumping.
When the power output is low you will get ABS and active handling codes.

UstaB-GS549

I'm pretty sure its normal for the system to run the battery down in 2 weeks or so if you don't drive it.

It's unlikely that you damaged the ABS jumping the battery.

These cars are strong, but have a lot of electrical gremlins due to solder joints failing. Removing lead from solder causes all kinds of problems that were not fully sorted out when these cars were built. Search the forum and either learn how to solder or find someone who can. It can save you money.

In the past 14 years mine has had the door locks, climate control & ABS repaired with a little bit of solder, flux and great DIY articles found on this forum.

Rob 02

When the car is running it doesn't rely on battery power unless the alternator isn't working properly. If it's bad the Alt is one of the easiest parts to change on this car.

Ooglie Googlie

Thanks for all the replies guys. I am new to this car and would like to learn as much as I can about it. This morning, the car started right up. I thought for sure the battery would be dead. But i am not out of the woods yet.
Would it be possible to install a cut off switch at the negative battery terminal until this problem is sorted out? This is in order to avoid having to jump start the car and possibly causing more damage.

Should I worry about this issue? I am still upset about it because I just bought the car and already I am having problems.

Rob 02

I wouldn't get too upset over these bugs. Most of us use a battery tender during storage.
You could install a cut off switch but you might loose memory settings (no big deal).

Ooglie Googlie

Thanks Rob. I feel a little better. I am going to install a battery cut off switch at the negative terminal today.
Ive also noticed when researching this issue that some people do use battery tenders like you said.
Can you please recommend one?

Rob 02

My battery charger has a tender feature built in for jell-cell and other battery types.

A lot of people here are using the Deltran (it's like a $50 item). You want the right one for your type of battery.


I'm using this Schumacher charger.

Ooglie Googlie

Just wanted to give everyone an update. I placed a multi-meter in series with the battery with the key out of the ignition, the under hood light removed and the doors shut.

I let the car sit for about 15 minutes for the computer to settle down.

Initially, the current draw went to .09 amperes for few seconds after connecting the meter but then bounced back up between .3 and .29 amperes and stayed there.

I have checked the interior lights including the glove compartment light and they were off.

Looks like I have my work cut out for me.

Rob 02

Have your alt checked for free at a parts store.

UstaB-GS549

After having to replace his battery, a friend with a 98 C5 was concerned about current draw when car was not running.

We used his clamp on ammeter to compare to my 02 Z06 with his car while parked side by side. The readings were exactly the same. I don't recall the number, but we were both surprised by how high the reading was. Maybe your .3 amp current draw is normal.

Except for winter, my car is pretty much a daily driver so it does not get much of a chance to draw down the battery. From December to April I just charge the battery and then disconnect the ground cable. In April I reconnect the cable and the battery starts it right up.

Ooglie Googlie

How can I verify that the BCM is the problem?

Is it possible to check the fuses under the dash with the drivers side door open?

As far as the current draw the meter was set at 10amps and the draw was about .3 amps which is 300mA, too much draw as you stated.

I have to tell you this whole situation is sickening to me. The car runs so good. Its such a shame Im having problems like this.

Any help you can give me to solve this problem is really appreciated.

Ooglie Googlie

Another update, after letting the car sit with the battery disconnected, the current draw after approximately 15 minutes was .03mA. I dont understand what caused this change. Is it possible the cold weather or letting the computer "reboot" solve the problem?

Im still going to keep my eye on it and utilize the cut off switch at the battery to be safe.