[328iDriver]

Hey all,

I am trying to identify the problem with my 2009 328i Sedan and I am somewhat confuse. So here is the story...
The car was on its second battery one day without and error codes or battery warnings, it wouldn't start on my driveway... No dash lights, no crank or noises of any kind, no locking/unlocking, completely dead. I tried jumping it from the engine bay with no success and also no sings of life (lights or noise etc)...this was weird!

I wasn't able to open the trunk so I couldn't get to the battery. (thanks BMW )

Later I tried one of those battery charging gadgets which gave me no reading on the battery, but after being connected for 48 hours it did allowed me to open the trunk, and without diagnosing it further I went to the dealer and bought a new battery of the same Ah/A. Installed the new battery as I have done before and the car started with no problems at all, and all seemed fine electronically, etc. No error codes, all good...

A few days of driving and again the car went dead, all symptoms exactly like first time, except this time I was at a store's parking lot. For a couple of days I tried all of the above with no success and I finally called the tow truck (didn't want the police towing it).

Tow truck wasn't a flatbed, so the guy had to lift the car from the rear. Tow brings it back to my driveway and leaves, to my surprise, I pressed the fob button and the car unlocked normally!!! then I try to start the car and it DOES start... everything seems to be in order, I let it run about 20 minutes and turn it off. I drove it a couple of times around town and on the third day the car is dead on my driveway again!

By the symptoms described above I don't see how it could be some of the more common things I found in this forum like the IBS, Alternator, Starter and/or Battery, can anyone think of what the problem could be?

Thanks

SP: here's some more details about the car

• 2009
• e90
• sedan
• auto
• 40K miles
• no accidents
• premium pkg
• sport pkg

[marvinstockman]

First, is the battery the same type as your original, meaning flooded/wet, or AGM (glass mat)? If not, it needs to be coded to the car. Capacity is not the issue.

Check all your battery connections.

Go get a cheap $10 multimeter, and check voltage at battery, with engine running. It should be about 13+ to 14+ volts. Compare to another car if you are unsure.

The voltage on a battery, without car running, and having sat overnight, should be about 12.5 volts. Again, compare to another car.

[e90yyc]

When you say “no error codes,” I think what you’re actually saying is that no error messages are popping up either in the cluster or on iDrive screen. Is this correct? If so, you still need to connect an acceptable scan tool (one that’s able to read BMW codes) and scan the car.

Based on what you’re describing, I don’t see how there could possibly be no codes stored.

[gbalthrop]

Originally Posted by 328iDriver

...2009 328i Sedan...Installed the new battery as I have done before and the car started with no problems at all, and all seemed fine electronically, etc. No error codes [WHAT Scan Tool used?], all good...A few days of driving and again the car went dead, all symptoms exactly like first time, except this time...Tow truck wasn't a flatbed, so the guy had to lift the car from the rear. Tow brings it back to my driveway and leaves, to my surprise, I pressed the fob button and the car unlocked normally!!! then I try to start the car and it DOES start... everything seems to be in order, I let it run about 20 minutes and turn it off. I drove it a couple of times around town and on the third day the car is dead on my driveway again!...can anyone think of what the problem could be?...

Since it unlocked & started normally after tow truck had moved it, obviously the new battery still had charge from alternator. So you have a loose battery B+ supply wire/ connector (12V+), or a loose Ground connection between battery (-) post and Chassis. Whatever is loose is "intermittent", working most of the time, until it DOESN'T, which makes diagnosis challenging.

Since you have not had an issue with power while the engine is running, or after "wakeup" when more current is flowing, it would seem that your issue is a corroded or loose connection.

If you have a simple, cheap DMM (Digital Multimeter) like the one available from HFT (Harbor Freight Tools) for $6, you can test for Voltage or continuity to ground when the "Gremlin is IN." You can ALSO try to "jiggle" the connectors listed below when interior lights won't light, to locate the problem source. When "Gremlin" is NOT present, and all is operating properly, the only thing you can do is start at the battery terminals:

1) Check for anything loose from (a) the (+) battery terminal, through the (b) X10209 smaller supply wire at the Power Distribution Panel (see details below), and work your way to (c) the JB (Junction Box) for the 12V+ or B+ wiring & Connectors;

2) Check the Ground side, starting with (a) the (-) battery terminal, and (b) the ground wire going to Chassis, making sure (c) the chassis connection is tight.

If your Remote Key is NOT unlocking the vehicle, no interior lights are on when you open the door, the radio does NOT function when you insert the Remote Key in the Insert Compartment, and the Instrument Cluster does NOT light when you press START, then either you have (A) a bad Ground Connection between the Battery (-) post and Chassis, OR (B) there is a bad connection between the Battery (+) post and the JB. There is a known issue with the B+ Connector at the JB on some models. That Connector is "X13020" on the right side of the JB fuse panel as shown in this TIS "Installation Location":
https://www.newtis.info/tisv2/a/en/e90-328i-lim/RKy9OeU

Here are the TIS Battery Supply to JB circuit diagram, and the Installation Location of X10209 where the cable that runs inside the car to the JB is attached to the Rear Power Distribution Panel on top of the Battery:
https://www.newtis.info/tisv2/a/en/e...ronics/jeKow6i
https://www.newtis.info/tisv2/a/en/e...lim/1VnZ6V3s86

Remember that there are SEPARATE B+ power supply Cables to (1) the Alternator & Starter, (2) the DME, and (3) the JB and all interior lights and controls, including the CAS (Lock & Unlock) and Radio. So if you had an issue with (3) the B+ Connector to the JB, you would still have 12V+ at the Jumpstart terminal under the hood, which is connected to the cable supplying power to the Starter & Alternator.

Please let us know what you find,
George