[namburger]

For background, I've had my e93 for over a year now with no issues, the car had upgraded turbos + idx12 + FBO (on stock dp).

I recently went stage2+ mhd and everything was running fine, no boost leaks or anything. Then the car started having battery issues, where the battery would go dead if I leave it in a garage for a few hours and wouldn't hold charge.

Until this morning, I noticed that the car started throwing random lights on the dash when I first started it and then they all disappeared. Then I went to driver the car and noticed that it's having problem pushing over 3000rpms at 3rd gear. No lights, no misfires, nothing. I didn't get a chance to log anything since I was on the way to bring it to a shop to get the battery replaced and had to hurry to work, although I did managed to read the codes and posting it below. I asked the shop and they said that the battery can definitely cause all type of issues for the DME and the code I read seems to adds up:

- DME active codes -
2AB4 - DME: DME, internal fault: RAM checksum.
2DEC - DME: Power management, battery.
2DED - DME: Power management, closed-circuit current violation.
2EE6 - DME: Coolant-temperature sensor, measurement range.

- DME shadow (inactive) codes -
2AAF - DME: Fuel pump, plausibility.
2D5F Reset

- Misc. information -
3/6/2024
MHD 3.2.0
Adapter: UNI 3.86_3.25 (up to date)
Voltage 13.33 V
Last flashed file : v10.0 stg 2+ 93_98
VIN: WBAWL73568PX44431
CAS VIN: WBAWL73568PX44431
HW: IJE0S
Factory software: 7626368
Current software: 7626368
ECU status: -

- Readiness -
Misfire: Complete.
Fuel System: Complete.
Components: Complete.
Catalyst: Complete.
Heated Catalyst: Not avail.
Evaporative System: Complete.
Secondary Air System: Not avail.
A/C Refrigerant: Not avail.
Oxygen Sensor: Complete.
Oxygen Sensor Heater: Complete.
EGR System: Not avail.

Question:
- Can MHD tuning causes problems to the battery?
- can bad battery causes the symptoms that I'm seeing?

I hope the casr will start driving better again when I pick it up today

[Warishuku]

Well, based on my experience, a bad battery definitely causes electronic random issues.

Once I let my car in my garage for months, and forgot to disconnect the negative in the battery, so it naturally got draing completely. After some charge, I started to use the car again but I constantly got weird electronic behaviours like ABS warnings, tilting lights, starting issues, I can't even reset the service alert anymore.

So my advice, be careful when using the car with a bad battery, I think that stuff can get damage, these cars are very sensitive and any out of spec power delivery can damage stuff.

[namburger]

Originally Posted by Warishuku

Well, based on my experience, a bad battery definitely causes electronic random issues.

Once I let my car in my garage for months, and forgot to disconnect the negative in the battery, so it naturally got draing completely. After some charge, I started to use the car again but I constantly got weird electronic behaviours like ABS warnings, tilting lights, starting issues, I can't even reset the service alert anymore.

So my advice, be careful when using the car with a bad battery, I think that stuff can get damage, these cars are very sensitive and any out of spec power delivery can damage stuff.

Apparently the shop did a health check on the battery and they think it's healthy, there is a parasidic draw... I think I know the issue, I recently self installed an aftermarket android auto/apple carplay unit and the car ran fine for about a month. However I added a back up cam and I'm pretty sure weird things started happening after that. I belive I may have tapped the cam power to a constant which may the drawing power constantly. Idk, I may have to do some test after getting my car back tomorrow, it's also getting the OFH gasket replaced.

It just feels weird to me that something like this ends up messing with power output of the car, though

[TiAgAu]

Originally Posted by namburger

Apparently the shop did a health check on the battery and they think it's healthy, there is a parasidic draw... I think I know the issue, I recently self installed an aftermarket android auto/apple carplay unit and the car ran fine for about a month. However I added a back up cam and I'm pretty sure weird things started happening after that. I belive I may have tapped the cam power to a constant which may the drawing power constantly. Idk, I may have to do some test after getting my car back tomorrow, it's also getting the OFH gasket replaced.

It just feels weird to me that something like this ends up messing with power output of the car, though

Your probably right. I did the same thing although i tapped in a reverse cam emulator causing parasitic draw. Couldn't find an accessory wire behind the headunit so went to cig lighter.

[namburger]

Originally Posted by TiAgAu

Your probably right. I did the same thing although i tapped in a reverse cam emulator causing parasitic draw. Couldn't find an accessory wire behind the headunit so went to cig lighter.

Humm, I'm still waiting to hear back from the shop and I'm getting pretty nervous for my baby
How does a parasitic draw cause lost in power performance? I mean the car could barely go pas 60mph and I was on full throttle the burbles were still there, tho

[TiAgAu]

Originally Posted by namburger

Humm, I'm still waiting to hear back from the shop and I'm getting pretty nervous for my baby
How does a parasitic draw cause lost in power performance? I mean the car could barely go pas 60mph and I was on full throttle the burbles were still there, tho

Well it doesnt effect performance. But its probably in limp mode due to other codes.

[namburger]

okay, got the car back, the shop told me they found a loose negative cable.. which is odd, since I've been driving around for a whole year without touching it.

Oh well, they cleared the code and the car is driving good now, I'm going to continue to monitor the battery though.