Denso 210 Amps Alternator

[Marcoose]

Hello, All.

After having battery discharging issues, local indy #1 said the OE alternator was not putting out the charge it was supposed to. He replaced it with a Denso 210 Amp. It seems, correct me if I'm wrong, the E89 (or specifically the 35is) takes a 170A alternator. The discharging woes continued, and I went to indy #2, who said the DME isn't 'seeing' the new alternator.

Questions:
1. Has anyone replaced the OE 170A alternator with a Denso 210A alternator ?
2. Was it plug and play, or you had to trick the DME to see the new alternator ?
3. Are there other BMW models with N54 engine that uses a 210A alternator ?

Thanks.

 

[B21]

Most E89s were fitted with the 210 amp version..

It’s plug n play between either version

Could be a communication fault as the alternator and DME talk to each other..the DME instructs the alternator what to do..

 

[flybobbie]

Is the ibs on the negative battery terminal ok?
Think this controls charging or connected to.

 

[B21]

Is the ibs on the negative battery terminal ok?
Think this controls charging or connected to.

That sends battery state to DME to determine charging requirements/ ability to take charge / what systems to turn off etc..

Maybe it could be an issue…unfortunately substituting it is often the only way of proving it either way,,

 

[Marcoose]

Is the ibs on the negative battery terminal ok?
Think this controls charging or connected to.

That sends battery state to DME to determine charging requirements/ ability to take charge / what systems to turn off etc..

Maybe it could be an issue…unfortunately substituting it is often the only way of proving it either way,,

Caught me there. Dunno.

I went to BMW of SF today. (Free coffee and doughnuts.) They said the OE alternator in stock for this car is a Valeo 170A. Only 2 left in stock in the US.

 

[The.Analyst]

It may be but either will work in the car