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All,
Unfortunately I am once again back with issues - fixed the MAF and 2 days later new issues.
I have a 02 330ci with about 180k - the car has always run great, after fixing the above issue, driving 80 on the highway the trans light came on (cog wheel with !), the car downshifted with a hard bag to 3rd gear and the charge light (red battery) came on...incidentally the brake, traction control and several other lights began to blink.
Came home, tested the voltage at the batt - 12.52 and was changing at 14.3. After leaving the car for several days I came back to a dead battery. Following 2 days of charging I load tested the batt, came out fine (4 years old) and was charging 14.5/16 although all the lights are still on. The code showing is P0444 (sensor) and P1892 (lean condition).
This leaves me wondering Alternator, computer, or buy a new car.
Wagon meister :)
BMW Tech Expert
Well neither one of those codes will cause the trans to go into safe mode.
You will need to get the trans ECU scanned, and that pocket scanner will not do that.
Darin
Current:
16 220i Active Tourer Platinsilver MET (C08)/Dakota Black (PDSW), P7ACA, P7LDA, P7LHA, P9BDA, 6sp Manual - Wife's new toy!
05 325it Electric Red(438)/Gray(N6TT) ZCW, ZSP 5sp Manual Back set cover, trunk mat, Euro Infra-Rot front windshield, and mud flaps! Mr. Wagon My new Winter car.
05 M3 Imolarot II(405)/Gray(N5TT) ZCW, ZPP 6sp Manual C.F. Lip, CSL diffuser, SSK, Euro Infra-Rot front windshield and a trunk liner! Mr. Go_Fast Stored for the Winter
Past:
95 318is Montreal Blue Met (297)/Beige(K1SN) RIP, killed by an Idiot.
84 M535i gray market Burgandy Rot Met/Black Leather Lowered by Intrax on bilies, poly everywhere, B&B cat back system, K&N, and a hitch! Da Beast - Still running w/400k+!
91 316i euro Tizianrot/Gray cloth - E-36 w/M-40 RIP, but great on gas! Best was 38 MPG
82 528i euro Saphire Blue Met/Blue Leather RIP
79 525 euro Green/Green RIP
79 318 Silver/Black - The first one that got it all started
M-Flight Member
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BMW CCA Member
Low voltage could do itOriginally Posted by dworthy
Member
BMW Tech Expert
The battery light comes on because the alternator isn't charging, and the voltage dropped. A serious voltage drops really upsets ALL the computers, and will certainly put the trans into limp mode.
If you had a real BMW diagnostic device that could talk to your computers, you'd almost certainly find low voltage codes in half a dozen of them. (A p-code reader is akin to an Ouija board....wouldn't know a transmission from a transvestite).
Note that a failure of the alternator to charge, especially intermittently, may well be a loose or dirty connection, not necessarily a faulty alternator. There are half a dozen connections necessary to make the alternator work.
IF you end up needing a new alternator, do NOT buy a "rebuilt" one at your local Autozoo. You want either a brand new Valeo, or a Bosch Factory Remanufactured part, in a black Bosch factory box. (The choice between these two will depend on which part your car has, Valeo or Bosch).
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Member
I removed the Alt and had it tested at the auto parts store - they indicated it needed replaced (ran maybe 10 seconds on the tester) the test mentioned the diodes. As the alt was actually sending 14 + volts to the battery I am going to replace the regulator/diode pack ($200 vs $35) rolling the dice on not needing the whole alt. The regulator is an actual Bosch replacement.
More when I test.
Member
As bmwdirtracer noted, the computers don’t like whacky voltages. Keep your fingers crossed that your alternator didn’t send alternating current (AC) out. Digital electronix hate AC. The Bosch voltage regulator should do the trick.
Member
GM - After replacement of the regulator, all of the listed issues have disappeared, currently charging at 14.3 and seems to be fine.
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