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Low Battery

D1JL

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#1
So I was working on my car and doing many things.
Opening and closing doors, turning lights on and off.
I totally forgot that I was running down the battery.

I finished my projects and planned to move the car.
Getting in, everything looked normal until I tried to start the engine.

Depressing the clutch and pushing the start button.
EVERYTHING WENT NUTS.

Of course the engine did not start.
However, all of the dash lights started to flash in a strange manner, the chime sounded, the NAV display did crazy things.

Needless to say, all of this scared the crap out of me.
I thought I had killed my car.

Having never seen this before.
I disconnected the things I was working on and it still the same thing.
I got out my code reader and tried to read/clear and codes I might have set only to get a code reading/clearing error.

After the panic subsided, I realized what I had done.
I connected my battery charger to correct the problem.

If I had not been so stupid and panicked I would have taken a video of this.

The point of this is for those that might see this in the future.
It may just be a LOW BATTERY.


Dave
 


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#2
Had a Monte Carlo towed because of the same symptoms! Car was freaking out. Car needed a battery!!!!
 


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#3
Well, if your battery is weak and you try to start and it is barely cranking you can fry your ecu and a number of other electrical systems. You have massive voltage spikes in that situation. Very dangerous to do... good thing you stopped and grabbed a charger instead of continuing to attempt
 


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D1JL

D1JL

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Thread Starter #4
Well, if your battery is weak and you try to start and it is barely cranking you can fry your ecu and a number of other electrical systems. You have massive voltage spikes in that situation. Very dangerous to do... good thing you stopped and grabbed a charger instead of continuing to attempt
To be clear, the starter did NOT crank at all (sorry not mentioned above).
As in older cars you get the clicking of the starter solenoid, this did NOT happen either.
Nothing happened except the dash going crazy.

I have found out since that this is a normal reaction for our cars to let you know of a low voltage condition.
As you know, this car does not have a voltage gauge.
I just had never seen it before and that is why I was not sure what had happened.

Please also put yourself in my mindset, I was just working on electrical things and thought I fried something.
Again my point was only to alert others incase they found themselves in a similar situation.

Your statement of massive voltage spikes does strike me as odd.
Only because of the fact that the battery voltage was LOW enough to not even allow the starter to crank.
I am curious as to where the spikes would come from?
I have worked on PCMs and BCMs for many years.
I don't know of any capacitors in the system large enough to do the damage you speak of (I may be wrong).
Except for working on my own cars, I retired from automotive repair a few years back.



Dave
 


Sekred

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#5
I have had this happen to me too because of low battery voltage. Once battery voltage drops below a certain level then the ECU won't allow the starter to engage. Out of interest 100% State of Charge > 12.6 volts, Specific Gravity 1.270. 0% State of Charge >11.9 volts, Specific Gravity 1.100 @ 26.7 C temp.
 




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