Could this be a 'grounding' issue? 99 C5

[Otter]

I went out to my car 60 minutes ago, got in, bumped the key (normally cranks and starts immediately), let off the key, no start. Turned the key off, retried and got nothing (no crank, silence). Pulled the key, opened the door, something seemed to reset (heard a click) so I closed the door and car started as normal. Mileage average was reset, radio was off, heater was on(was off) and probably other things changed. Went and got a sandwich, tried locking/unlocking via key fob (didn't work, was working this morning). Anyway, car started fine when I left sandwich shop and got back to work (key fob still didn't work). Reset codes before I came in, will check them when I get home this evening.

From the ton of reading I have read here over the years, this seems like I should start by cleaning all the grounds, does that sound like a good place to start? Granted, I haven't seen any codes yet and my ideas could change but it seems to me like a classic ground issue.

Thoughts? and thanks for any replies.

 

[gmjunkie]

grounds,Grounds,GROUNDS.........High Resistance or Non-Existent Grounds Make Electronics do weird Sh*t!~!

That's where I'd start!

 

[Otter]

grounds,Grounds,GROUNDS.........High Resistance or Non-Existent Grounds Make Electronics do weird Sh*t!~!

That's where I'd start!

:BOW Thank you, was hoping I would hear from you or half a dozen others whose opinions I value. Hat is off to you, sir, for your help and your help to others.

 

[Z16#952]

I have had similar problems like the one you experienced and found that the battery was the cause. These cars seem to use up batteries in a hurry.

 

[Otter]

I have had similar problems like the one you experienced and found that the battery was the cause. These cars seem to use up batteries in a hurry.

That crossed my mind, too. Might invest in a battery this weekend (have had the car 15 months, no idea how old the battery is), along with cleaning the grounds. Appreciate your reply, thank you

 

[timfitz63]

... tried locking/unlocking via key fob (didn't work, was working this morning). Anyway, car started fine when I left sandwich shop and got back to work (key fob still didn't work)...

I suspect this is a secondary issue; if everything got electrically reset, as it were, the RFA system probably lost the most-recent security code assigned to the key fob(s). This often happens when the battery is disconnected or dies. All you should have to do is get near the car with your key fob(s) and -- one at a time -- press and hold the LOCK and UNLOCK buttons simultaneously for about seven seconds; if the fob is successfully resynchronized with the RFA, the horn will 'chirp.' Consult your Owner's Manual for details on resynchronizing the [key fob] transmitter.

 

[Hib Halverson]

First, inspect the battery. Remove the cables, clean posts and cable ends, reinstall the cables and tighten.

Then road test.

 

[dadaroo]

By all means don't share the codes with us. Sorry, but you ask for help and that can be important.

 

[LLC5]

I went out to my car 60 minutes ago, got in, bumped the key (normally cranks and starts immediately), let off the key, no start. Turned the key off, retried and got nothing (no crank, silence). Pulled the key, opened the door, something seemed to reset (heard a click) so I closed the door and car started as normal. Mileage average was reset, radio was off, heater was on(was off) and probably other things changed. Went and got a sandwich, tried locking/unlocking via key fob (didn't work, was working this morning). Anyway, car started fine when I left sandwich shop and got back to work (key fob still didn't work). Reset codes before I came in, will check them when I get home this evening.

From the ton of reading I have read here over the years, this seems like I should start by cleaning all the grounds, does that sound like a good place to start? Granted, I haven't seen any codes yet and my ideas could change but it seems to me like a classic ground issue.

Thoughts? and thanks for any replies.

I would start with a proper load test of the battery, battery cable cleaning, and proper tightening of the cables, making sure that you cannot twist the cables side to side after tightening the hold down bolt. Since you already reset your codes, post any codes that come back. Good luck with it.

 

[Otter]

By all means don't share the codes with us. Sorry, but you ask for help and that can be important.

Had to meet wife for dinner and just got home, will check in morning. You're more eager than I to get to the bottom of this..thanks, appreciate it.

LLC5 - thanks, thats the plan for tomorrow. thanks. Looked at a vid from Froggy, will clean and test battery plus check out the 3 main grounds around the engine.

Hib - thank you, as I told LLC5, I will check out everything in the morn.

 

[Otter]

Okay. Ton of codes, mostly all "Loss of communications", wrote them down but can't find the paper I wrote them on, but here is what I did.

1. Test of battery was 12.2, started it was 13.8
2. Pulled and cleaned battery cables.
3. Pulled, cleaned ground connectors in engine bay, all terminals cleaned and reseated with dielectric grease. Connector on drivers side had a bit of corrosion, others were corrosion free.
4. Torqued battery cables back on. (did notice that neg. cable seemed kinda loose when I took it off)
5. Cleared codes, drove for 30 minutes, came home, no codes.
6. Relearned Fob, all cool there

Car seems fine now, noticed last night on drive home that clock/radio lights were pulsing with RPMs, its not doing that now. Not sure what was causing the problem but I feel it was either the drivers side ground connector or the neg batt cable wasn't torqued properly.

Appreciate all comments/clues/thoughts, any of ya ever in southern MD, I owe ya a crab cake and beer.

Thanks

 

[kpic]

Check the battery ground. A simple drilled hole and a self-tapping screw cured my C5's problems.

 

[dadaroo]

12.2 volts at startup is too low. The electronics do not like low voltage. The starter likes current more than voltage.

A fully charged battery should be 12.6v or more. Sounds like a weak battery.

It's not 12 volts it's 12.6 because each cell is 2.1 volts.

If the battery is

12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained

 

[Otter]

Thanks, Dadaroo, looks like I will look into replacing the battery to be safe.