After changing voltage regulator, car won't charge until revved

[jvictormp]

hi guys

just replaced my voltage regulator for a brand new valeo 599221, old one had worn brushes.

it's charging well, voltage is 14.5V

Problem is, alternator doesn't charge at engine startup. I need to revv it to 2k RPM in order for the alternator to start charging.

What could be it?

[tdott]

Scan it with ISTA/INPA/etc and see what fault is there.

[jvictormp]

Originally Posted by tdott

Scan it with ISTA/INPA/etc and see what fault is there.

So I made it, and there is the fault codes list after cleaning error memory, historical memory and information memory, and turning engine on:


E R R O R M E M O R Y
-----------------------
Date: 21.12.2020 15:11:05
Model: E89X
Scope: all control module
JobStatus: OKAY
Quantity: 25
-----------------------------------------------------------------
ADR Gen. name JobStatus
36 TEL/MULF ERROR_ECU_SUBFUNCTION_NOT_SUPPORTED__INVALID_FORMA T
-----------------------------------------------------------------
ADR Gen. name JobStatus Number of errors•
Error code Kind of error
00 JBBF OKAY No Error stored•
01 MRS OKAY 1 Error stored•
93FB E0•
12 DME/DDE OKAY 2 Error stored•
2739 08•
278C 48•
27 PGS OKAY 1 Error stored•
A0A7 60•
37 AMP OKAY No Error stored•
39 EDC OKAY 4 Error stored•
5FD4 E2•
5FF1 28•
5FF7 24•
5FF8 64•
3C CDC OKAY No Error stored•
3F ASK OKAY No Error stored•
40 CAS OKAY 2 Error stored•
A0B5 61•
A0BA 22•
41 DWA OKAY No Error stored•
47 ANTTU OKAY No Error stored•
4B VIDEO OKAY No Error stored•
50 SINE OKAY No Error stored•
56 FZD OKAY 1 Error stored•
A670 28•
60 KOMBI OKAY No Error stored•
62 MOSTGW OKAY No Error stored•
63 MASK/CCC OKAY No Error stored•
67 ZBE OKAY No Error stored•
6D FAS OKAY No Error stored•
6E BFS OKAY No Error stored•
72 FRM OKAY 1 Error stored•
9CBF 64•
73 CID OKAY No Error stored•
78 KLIMA OKAY No Error stored•
A0 CCC OKAY No Error stored•
================================================== ===============

[drwankel]

A bit out of left field here. I had another car (not bmw) which I retrofitted a larger alternator in from another vehicle. I accidentally miswired the voltage regulator (wired it backwards) and the behavior when this happened was exactly what you described. The alternator wouldnt kick on until I revved it a little after startup.

Thinking about this, it is possible that you might have a bad connection to the voltage regulator on the alternator. Wire could be broken, or a pin in the connector isn't making contact. Might want to thoroughly examine the wiring and connector.

[Helmsman]

And once you revved up, it continue to charge also at lower rpm/idle?

[jvictormp]

Yes. Works forever. Until next engine turn off.

I'm willing to check it in the oscilloscope, to see if the voltage wave is alright. If it looks like the two faulty ones below, the alternator is bad.

[tdott]

Scan/Post the details for the 278C error, may be your problem.