[mcmark]

One time! I coded my bmw 535I. after the car cannot changer the battery when I am driving my car. Whats the problem is?


(The blue logo doesn't work when I am driving)

[ezaircon4jc]

Originally Posted by mcmark

One time! I coded my bmw 535I. after the car cannot changer the battery when I am driving my car. Whats the problem is?

Attachment 1664573
(The blue logo doesn't work when I am driving)

The battery only charges when coasting. Watch that gauge when you lift off the throttle.

[mfshin]

I have the same problem.
I believe battery is charging ok, it's just that when coasting that blue light does not come on (never) and it's been going on for months.
Amyone know how I can get this blue light come on again?

[ezaircon4jc]

Originally Posted by mfshin

I have the same problem.
I believe battery is charging OK, it's just that when coasting that blue light does not come on (never) and it's been going on for months.
Anyone know how I can get this blue light come on again?

What year? The 2017 5 and some newer (don't know when it started) 3's have a coasting mode where the trans goes into neutral and the alternator doesn't engage and charge the battery.

Why do you think the battery is still charging? Is your foot on the throttle even just a little? A trip to the dealer or indy is probably your next step.

[Surly73]

Originally Posted by mfshin

I have the same problem.
I believe battery is charging ok, it's just that when coasting that blue light does not come on (never) and it's been going on for months.
Amyone know how I can get this blue light come on again?

My recommendation - don't obsess about the light. Although it's odd that it doesn't come on, it's all just software. Measure the system voltage. Just because a little blue bar designed by Marketing doesn't light doesn't mean your battery isn't being charged.

Assuming you have an AGM type battery (which all of us with F10s seem to) then it should measure 14.8VDC when it is charging at max rate. You should see this at some point when the car is running. This is a system voltage which will recharge the battery as quickly as it is able.

A voltage suitable for "float charge" when the battery is near fully charged is more like 14VDC.