2016 V6 coupe, this morning noticed that the switch light stays illuminated even though the power is not on, also got a message the "Battery is low, start car immediately" or something like that.

Question is, is the switch supposed to stay illuminated after you shut everything down, or not?

Thanks.

 

This happened to mine when I first brought it home. I'd get the low battery warning after being parked for more than 24 hours or so. Then I noticed the center console red hazard switch light as well as the yellow door lock lights were staying on indefinitely, which clearly looked suspicious.

I fixed the issue by disconnecting the positive lead from the battery for about 15 seconds and then reconnecting. Now the hazard/lock lights turn off after about 2 minutes and I haven't had any low battery issues since.

Don't forget to check/reset the auto stops for the power windows after you reconnect everything!

 

+1. Right solution.

 

Easy enough, thank you gentlemen.

 

So if the red hazard triangle stays on, it means battery is low?

 

If it stays on for more than 10 minutes after you shut off the car, it means you have to disconnect the battery for at least 10-15 seconds to reboot the battery control module. Otherwise your battery will fully discharge over a 3-4 day timeframe if the car stays parked.

 

Thank you. Do i disconnect both pos and neg cables? Or just pos?

what about the secondary small battery?

 

The correct way to reset the BSM is to disconnect the negative terminal from the battery post (which has the battery monitor built into it) and leave it floating for 10-15 seconds as mentioned. You can ignore the second battery if present. Don't connect the leads together - it is not needed to reset the BSM.

You can reset it by disconnecting the positive terminal instead, but you might get a small arc or a little shock if you are grounded to the bodywork at the same time.

 

+1.

 

Just to straighten the cause versus effect here............

It's not an "indicator" of low battery. It's a visible symptom of the problem that your electrical system is not fully hibernated. That lack of full hibernation (cause) results in a draining battery and thus ultimately, over time, a "low batter" warning (effect).

Desert Hiker

 

thank you. Battery in the trunk, or the post in the engine will suffice? The battery in the trunk has the pos terminal easily accessible but the neg is tucked under the trunk's plastic liner

 

In the trunk. That is where the BSM is (it is attached to the negative battery post).

 

thanks!

hope it fixes the issue. It occured after using the obd2 port. Issue is, im using the pearl rearvision camera so the obd2 port needs to permanently be used with their wifi/Bluetooth transmitter

 

I'd be interested to find out if you can return the control module to normal operation with the reset while the camera is still connected.

 

disconnected the battery and the hazard light is still on

returning the camera. Its draining power from the obd2 port all day long even with the car off/locked

 

So I've run into this same issue over the past couple months and just had to disconnect now (which worked great, thanks!); but does anyone know the trigger that's causing the fail?

Mine always tends to occur relatively shortly after an autocross event; wherein I keep my car locked with the top down for an extended amount of time; but coupes are apparently affected as well; so I'm guessing its not the convertible top causing it.

I feel like there's some konami code Im secretly entering by turning on/off headlights or interior lights; which triggers the fail. The last thing I did touch (electrically) yesterday was turning off the interior ceiling light; which would be a weird thing to cause the issue (but thats a wild guess).

I'd love to entertain some high level hypotheses or just flat out guesses. Because its driving me insane....

 

The hazard light remaining illuminated after 15 minutes is simply the indicator that the computers have not shut down and that therefore a battery drain is continuing. The light being illuminated is not a defect! It is a warning mechanism.

What causes the failure of the computers to shut down? Almost always it is the fact that an OBDII unit has been plugged in and remains plugged in, or that it has not been shut off before being removed from the OBDII port.
This is very common after official emissions checks.

The solution? Remove the negative battery connection from the stud on the trunk floor for 30 seconds. Reconnect. Done. Everything is now reset. You might, but only might, have to reset the window operation.

If you lock the car, the systems will shut down normally in about 15 minutes and the hazard light will go off. If you leave the car unlocked the light will remain on for up to a half hour before the systems shut down. If you have locked the car and the hazard light is still illuminated after 15 to 20 minutes, do the reset as described above.

Again: the fact that the hazard light is on is NOT the problem. It is the indicator that there is a continuing battery drain.

 

Morning all,

This might cause some 'flak' here from those that believe things written by professionals must be true .

As long as you disconnect the battery at either post for 15 mins you will be fine. Disconnecting the negative side is a PITA but the positive is easy and as an IEEE engineer I can assure you that the terminal you choose makes absolutely no difference.

Electrons flow from the negative terminal, through the system to the positive terminal where the circuit connection is completed. If you disconnect the positive it has exactly the same effect as in order for electricity to flow the circuit to the battery must be complete - otherwise no flow - no power - anywhere.

The purist might say that disconnecting the negative is the only way as it cuts off the electron supply at the source - however the electrons cannot flow at all unless they have a return path so either side will totally eliminate any electrical flow.

My car also suffers from the need to do a reset whenever an OBD scanner has been plugged in and I alway disconnect the positive at the battery which works fine.

 

That's true and cool and all until your wrench slips and/or comes into contact with something. Not required, but It's a good safe habit though.

 

Excellent point there, thank you. Indeed a wrench connecting the pos terminal to ground could be a big problem and so care is definitely required .