Battery light on, battery and alternator checked

[MyGT86Yas]

Hello all,

Hoping you guys can help identify the issue. My car was rear ended half year ago and it was at a shop for over a month, ever since the battery light stays on. I didn't feel any abnormal about the car so I didn't do anything about it.

One night when I loaded a new map onto the ECU, the car started and moved, but it stalled at low rpm when rolling to a stop. First, I went to O'Reilly and was told the battery was dying, so I replaced the battery at Costco. Car started normal but the battery light still on. It was fine until two days ago when I was driving in stop and go traffic and the same thing happened again. The car stalled twice and I had to rev it high in order to keep it from stalling.

One new problem is that when I press the clutch and leave the car in gear, the engine will rev to ~3000rpm and hold until I shift to neutral, then its back to normal idle. Went to O'Reilly again and they told me the battery, alternator, and starter are all good!

Any help will be appreciated!!!

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[geraldjust]

so Here is what i can come up with, are you sure they are fine? like they checked the voltage on the battery and that its atleast around 13.8 though 14.2 when idling. Did you swap either the alternator or the current sensor in the negative battery terminal. your car is a 17+ car correct? well reason i ask about that is that the ECUs for those cars actually handle the current sensor differently because on the older 13 though 16 cars it was old school signals. the 17+ cars the alternator and current sensor are "lin" based communication. Maybe the rom controls this too?

[MyGT86Yas]

Originally Posted by geraldjust

so Here is what i can come up with, are you sure they are fine? like they checked the voltage on the battery and that its atleast around 13.8 though 14.2 when idling. Did you swap either the alternator or the current sensor in the negative battery terminal. your car is a 17+ car correct? well reason i ask about that is that the ECUs for those cars actually handle the current sensor differently because on the older 13 though 16 cars it was old school signals. the 17+ cars the alternator and current sensor are "lin" based communication. Maybe the rom controls this too?

Thanks for the help! I kept my eyes on the battery voltage gauge and it stays constant at ~14V so I assume the battery is fine, and the alternator is stock. I also suspected the alternator was causing the problems because it was slightly modified when the supercharger was installed (edlebrock kit from 13-16 MY, had some fitment issue with the connector on top). But O'Reilly told me the alternator is fine so I'm not sure.

Will a bad alternator cause the engine to rev up when car in gear and clutch pressed?

[churchx]

"loaded new map on ecu", "will rev upto 3000" .. i'd rather expect some extra feature misbehaving in tune, eg. flat-foot-shifting or launch control, not something mechanical.

[steve99]

Hmmm
Lot of mods here


So your car is a 2017
Its been in an accident
After accident battery\alteranot warning light​ is on


Its had a supercharger fitted and ecu tune done


Was the supercharger and tune on the car before accident and did it run ok before accident. Ie it didn't do rev up tging and it didnt have battery waening light.


Now im assuming the new tune was loaded after accident ??


What is ecu calid of the tune like ZA1JK00C


if your tuning with ecutek what is the racerom revisison on tune like racerom 9 10 or 11

[MyGT86Yas]

Originally Posted by churchx

"loaded new map on ecu", "will rev upto 3000" .. i'd rather expect some extra feature misbehaving in tune, eg. flat-foot-shifting or launch control, not something mechanical.

I thought about it too but I couldn't replicate and log it. And it does sound liek a tune problem as it only rev to 3k rpm when in gear, if I put it in neutral then it's back to normal.

[MyGT86Yas]

Originally Posted by steve99

Hmmm
Lot of mods here


So your car is a 2017
Its been in an accident
After accident battery\alteranot warning light​ is on


Its had a supercharger fitted and ecu tune done


Was the supercharger and tune on the car before accident and did it run ok before accident. Ie it didn't do rev up tging and it didnt have battery waening light.


Now im assuming the new tune was loaded after accident ??


What is ecu calid of the tune like ZA1JK00C


if your tuning with ecutek what is the racerom revisison on tune like racerom 9 10 or 11

The tune was fine before accident, no battery light and no issue starting.
The tuner revised the tune after I replaced the leaky actuator valve on the SC.
Calid: ZA1JK00C Racerom version: 25482
Since you asked about the map info, do you suspect the tune was the cause more than a mechanical issue?

[steve99]

Originally Posted by MyGT86Yas

The tune was fine before accident, no battery light and no issue starting.
The tuner revised the tune after I replaced the leaky actuator valve on the SC.
Calid: ZA1JK00C Racerom version: 25482
Since you asked about the map info, do you suspect the tune was the cause more than a mechanical issue?

Ok if previois tune was fine then its probably not problem with old tune. If it wasnt racerom 10 based.


The later tune is suspect



Racerom 25482 sound like an early version of racerom 10.x which was full of bugs so bad ecutek actualy pulled racerom 10 support for the 2017+ cars. You want to be on racerom 11.1 whjch is patch 38208. Or the old raceom 9.1 whjch is 24256. Anything in between you want to avoid on 2017+ cars .


Basjcly you want to avoid racerom 10.x either use ,9.1 or 11.1 or later version if it comes out



But i stil! Think you have a hardware issue causing battery light.

[wparsons]

Battery light means it's not charging (or the ECU thinks it isn't). If you're seeing 14v at idle, then the alternator is fine. With the car not running the battery will have a resting voltage closer to 12v.

If you're seeing 14v measured, and the light is on, then there's an issue somewhere that the ECU isn't seeing the full voltage. Can you log battery voltage in EcuTek, if so that's a good place to start. Compare the logged voltage to a voltmeter directly on the battery.

[finch1750]

Was the stall only right after loading the new map? It takes time for the ECU to learn and that is fairly common along with delayed throttle response for a little bit.

Does the map have flat foot shifting? If the 3K happens in gear with the clutch down maybe it's an issue with that? I'm not as knowledgeable in this area as the others here but just thoughts that crossed my mind reading.

[MyGT86Yas]

Originally Posted by wparsons

Battery light means it's not charging (or the ECU thinks it isn't). If you're seeing 14v at idle, then the alternator is fine. With the car not running the battery will have a resting voltage closer to 12v.

If you're seeing 14v measured, and the light is on, then there's an issue somewhere that the ECU isn't seeing the full voltage. Can you log battery voltage in EcuTek, if so that's a good place to start. Compare the logged voltage to a voltmeter directly on the battery.

The voltmeter always stay at 14V with the new battery. I will try to log the voltage, thanks!

[MyGT86Yas]

Originally Posted by finch1750

Was the stall only right after loading the new map? It takes time for the ECU to learn and that is fairly common along with delayed throttle response for a little bit.

Does the map have flat foot shifting? If the 3K happens in gear with the clutch down maybe it's an issue with that? I'm not as knowledgeable in this area as the others here but just thoughts that crossed my mind reading.

That's what I thought when it happened for the first time. Then it happened out of nowhere a few months later and I didn't change any ECU setting in between.
Now you asked I'd find the maps weird, the tune was supposed to come with different maps with some racecom features like flat foot shifting and rev-matching. But I don't think there are racecom features in it.