SES light and disconnected battery

charlie fairmont · 05-07-2015, 12:53 PM

A few fays ago I wired trailer lighting into the car. All I really did was connect the trailer harness to power and ground--everything else was plug and play. To do this, I disconnected the negative terminal. I hooked everything back up and the car was fine. I had to reset the time and that was it. Drove it for about a day and a half and everything was fine. On my way to work, the SES light came on. Ive only had the car a week so I called and set up an appt to bring it back to the dealer. Last night, fearing some potential warranty BS from the dealer, I again disconnected the negative terminal and then removed the trailer lighting power and ground. Buttoned everything back up, started the car and again reset the clock. Car runs fine and the SES light went away(though this was not the purpose of me disconnecting the battery). The appt with the dealer is still scheduled for tomorrow a.m. Have I screwed myself somehow? I'm wondering 1) if the code will be retrievable, and 2) if I am guilty of hurting something by disconnecting the battery. Thanks for any insight.

Persian Whisperjet · 05-07-2015, 12:57 PM

Charlie I don't see why hooking up a trailer wiring harness would void your warranty.

Hoooper · 05-07-2015, 01:02 PM

the electrical system is really finicky and poorly thought out on this car. You wouldnt be the first person to cause an issue simply by disconnecting and reconnecting the battery. If you did, IMO it should still be covered by warranty because if theyre going to design a system so sensitive it can be messed up by disconnecting the battery they are responsible for that.

charlie fairmont · 05-07-2015, 08:31 PM

Thanks fellas, good points that will definitely be my arguments if any arguing needs to occur. Is it even worth going now that the code is gone due to battery disconnect? Does the code get lost on reset?

Persian Whisperjet · 05-07-2015, 08:41 PM

I am a sample size of one, but my experience was the techs were too casual not too inquisitive. Maybe if you had a blown engine....

charlie fairmont · 05-07-2015, 09:17 PM

Oh, no, you guys had already convinced me I needn't worry about warranty. With my last post, I was simply wondering if I would be wasting time. While not overly burdensome, a trip to the dealer is still a bit out of the way. I'm tempted to think the code is stored and still retrievable after the reset, but i am not positive. I wouldn't go if I knew the code code not be pulled.

05-07-2015, 12:53 PM	#1
charlie fairmont Captain 506 Rep 603 Posts Drives: His & hers, GC & X5 Join Date: May 2015 Location: Jax, FL iTrader: (0)	SES light and disconnected battery A few fays ago I wired trailer lighting into the car. All I really did was connect the trailer harness to power and ground--everything else was plug and play. To do this, I disconnected the negative terminal. I hooked everything back up and the car was fine. I had to reset the time and that was it. Drove it for about a day and a half and everything was fine. On my way to work, the SES light came on. Ive only had the car a week so I called and set up an appt to bring it back to the dealer. Last night, fearing some potential warranty BS from the dealer, I again disconnected the negative terminal and then removed the trailer lighting power and ground. Buttoned everything back up, started the car and again reset the clock. Car runs fine and the SES light went away(though this was not the purpose of me disconnecting the battery). The appt with the dealer is still scheduled for tomorrow a.m. Have I screwed myself somehow? I'm wondering 1) if the code will be retrievable, and 2) if I am guilty of hurting something by disconnecting the battery. Thanks for any insight.
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05-07-2015, 12:57 PM	#2
Persian Whisperjet Kind of a Big Deal 171 Rep 857 Posts Drives: 2011 335d Join Date: Dec 2012 Location: Washington, D.C. iTrader: (0)	Charlie I don't see why hooking up a trailer wiring harness would void your warranty. __________________
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05-07-2015, 01:02 PM	#3
Hoooper Colonel 213 Rep 2,210 Posts Drives: 335D Join Date: Jun 2013 Location: Petaluma, CA iTrader: (0)	the electrical system is really finicky and poorly thought out on this car. You wouldnt be the first person to cause an issue simply by disconnecting and reconnecting the battery. If you did, IMO it should still be covered by warranty because if theyre going to design a system so sensitive it can be messed up by disconnecting the battery they are responsible for that.
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05-07-2015, 08:31 PM	#4
charlie fairmont Captain 506 Rep 603 Posts Drives: His & hers, GC & X5 Join Date: May 2015 Location: Jax, FL iTrader: (0)	Thanks fellas, good points that will definitely be my arguments if any arguing needs to occur. Is it even worth going now that the code is gone due to battery disconnect? Does the code get lost on reset?
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05-07-2015, 08:41 PM	#5
Persian Whisperjet Kind of a Big Deal 171 Rep 857 Posts Drives: 2011 335d Join Date: Dec 2012 Location: Washington, D.C. iTrader: (0)	I am a sample size of one, but my experience was the techs were too casual not too inquisitive. Maybe if you had a blown engine....
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05-07-2015, 09:17 PM	#6
charlie fairmont Captain 506 Rep 603 Posts Drives: His & hers, GC & X5 Join Date: May 2015 Location: Jax, FL iTrader: (0)	Oh, no, you guys had already convinced me I needn't worry about warranty. With my last post, I was simply wondering if I would be wasting time. While not overly burdensome, a trip to the dealer is still a bit out of the way. I'm tempted to think the code is stored and still retrievable after the reset, but i am not positive. I wouldn't go if I knew the code code not be pulled.
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