New battery & Alternator causing Trans. Failsafe Prog

[sgrice]

Let's see: Parasitic drain, battery issues, trans fail, general elecrical weirdness - this all sounds familiar. Here's a sort of wild guess, but has the ignition switch been considered yet?

As revealed in the "Salty Dog" posting here on xoutpost ( https://xoutpost.com/bmw-sav-forums/...t-restart.html )about multiple electrical issues (including trans fail safe -as seen in the second picture of his post), the ignition switch can cause a bunch of seemingly unrelated electrical issues.

Maybe lightning is striking twice for our Australian friends?

[wpoll]

Originally Posted by mcfee03

Also, I thought the fact my Engine runs after the MAF is disconnected could mean the MAF is causing the trans fail-safe? Or will trans fail-safe mode keep the engine running even if the MAF is working?

The engine will run with the MAF disconnected - that's normal and unlikely to have anything to do with your current issues.

[mcfee03]

Originally Posted by sgrice

Let's see: Parasitic drain, battery issues, trans fail, general elecrical weirdness - this all sounds familiar. Here's a sort of wild guess, but has the ignition switch been considered yet?

As revealed in the "Salty Dog" posting here on xoutpost ( https://xoutpost.com/bmw-sav-forums/...t-restart.html )

I read through that thread - but I haven't got issues with sstarting.that seems Dog be the issue for "Salty Dog". Issue with starting initially was a flat battery (not driven for 5 months while did ccv, disa, alternator, aux water pump)

How do you know I've got Parasitic Drain?

I just tried pulling fuses, such as the cigarette lighter and rear window lifts. However, not sure I'm doing it right as the rear windows still worked (didn't test cigarette).

Please help- what is next to try here?

EVEN if it seems super obvious, just say it! please.

[Fifty150hs]

Originally Posted by mcfee03

I read through that thread - but I haven't got issues with sstarting.that seems Dog be the issue for "Salty Dog". Issue with starting initially was a flat battery (not driven for 5 months while did ccv, disa, alternator, aux water pump)

How do you know I've got Parasitic Drain?

I just tried pulling fuses, such as the cigarette lighter and rear window lifts. However, not sure I'm doing it right as the rear windows still worked (didn't test cigarette).

Please help- what is next to try here?

EVEN if it seems super obvious, just say it! please.

The usual culprits for parasitic drain are the NAV if you have it, the TCU if you have it and the FSR which you will have. However, as others have noted, with your random electrical issues it would be worthwhile checking the ignition switch.

[mcfee03]

Originally Posted by Fifty150hs

with your random electrical issues it would be worthwhile checking the ignition switch.

Ok, but FYI I did mention I have had no issues with starting.

How do I check the ignition switch is functioning fine?

[Fifty150hs]

Originally Posted by mcfee03

Ok, but FYI I did mention I have had no issues with starting.

How do I check the ignition switch is functioning fine?

I know you aren't having starting trouble. The ignition switch can cause a bunch of different problems that seem really random. Pull the switch hit it with contact cleaner and test with a DMM. The Bentley manual should tell you what wires go to where.

I forget, have you had the codes read?

[wpoll]

Originally Posted by Fifty150hs

I forget, have you had the codes read?

I was about to ask the same question. At this point in the process, it may be that diagnosis cannot continue until a full error read out (using INPA, P.A. Soft etc.) is done.

Because so many systems have been involved in the work you have done, the range of possibilities is rather large....

[mcfee03]

Originally Posted by Fifty150hs

Pull the switch hit it with contact cleaner and test with a DMM. The Bentley manual should tell you what wires go to where.

I forget, have you had the codes read?

It is the P0102 Mass airflow fault (sometimes pending). I don't have the Bentley manual, or a DNA yet. Any way of testing without one?

[wpoll]

Originally Posted by mcfee03

It is the P0102 Mass airflow fault (sometimes pending). I don't have the Bentley manual, or a DNA yet. Any way of testing without one?

That code looks like a generic reader code - not from BMW software. What reader are you using?

[mcfee03]

Originally Posted by wpoll

That code looks like a generic reader code - not from BMW software. What reader are you using?

The ELM327 with Torque Pro mobile app. Specifically this model I have also been able to clear the faults with it, but the failsafe comes back after a few seconds