Parasitic Battery Drain Diagnosis - EDC Module?

[rantarM3]

I've been working to diagnose an "increased battery discharge" (cc-id 415) error that appears whenever my car (2011 E90 M3 ZCP) has been sitting for a bit (such as overnight). I hope some of you will confirm my diagnosis and would appreciate any input.

The battery was replaced a couple of weeks ago because of the 415 error and because the battery seemed to not be holding its charge (also, the battery was 4 years old and in Florida, that's about the expected life). Also, I had recently purchased a Blue-Point intelligent battery charger and set it to 10 volts, but it just seemed to be cycling in an odd fashion (i.e., not what I expected). Once I left the car off the charger and the battery completely died in a few days.

The battery was replaced with a new one of the same type (OEM BMW) and had a reputable local shop registered it. The shop mentioned that when they registered the battery they found about 50 error codes; but they agreed that perhaps they resulted from the low voltage. The codes were cleared and off I went thinking all was well. I checked that the registration took after getting my updated Carly adapter.

Unfortunately, the error continued to appear every time the key was inserted (once I got a DSC error and once an EDC error instead). If I started the car, shut it off, and immediately restarted it, there would be no error message. I checked the battery voltage (@ under hood terminals) over the course of a week and found that it was dropping at a steady rate but seemingly too high (0.6 volts per day). I did not checked the current draw yet, but my guess is that there is a parasitic draw.

After researching online it became apparent that the battery might be fine and that a bad EDC module might be the culprit. Mike Benvo mentioned in a thread that a bad EDC module could result in the start/stop button remaining illuminated for a long time after the car should have gone into sleep mode. Sure enough, my start/stop button stayed illuminated indefinitely (I do not have comfort access).

I pulled error codes (via Carly) on two separate occasions. While there were some other seemingly random codes, the same 7 EDC related faults appeared each time. They were:

Electronic damper / Elektronische Daempfer

• Fault Code: 005FF0
• Fault Explanation: :CAN vehicle speed: timeout or invalid
  
• Fault Code: 005FF5
• Fault Explanation: :CAN outside temperature: Timeout or invalid
  
• Fault Code: 005FF6
• Fault Explanation: :CAN Mileage: Timeout or invalid
  
• Fault Code: 005FF7
• Fault Explanation: :CAN steering angle: Timeout or invalid
  
• Fault Code: 005FF8
• Fault Explanation: :CAN-wheel speeds: Timeout or invalid
  
• Fault Code: 005FFD
• Fault Explanation: eviation WakeUp line too big
  
• Fault Code: 005FFF
• Fault Explanation: :CAN Terminal Status: timeout or invalid

A test drive confirmed that the EDC remained in the same state ( i.e., would not switch modes). To confirm an EDC module failure I parked the car and pulled both EDC fuses (one is 20 amps and the other is 5 amps) to see if the start/stop button would go dark. Pulling the 20 amp fuse did nothing, but after removing the 5 amp fuse, the start/stop button finally went dark within a minute or so of shutting the ignition and removing the key. Leaving the 20 amp fuse in place but the 5 amp fuse out allowed the battery charger to charge the battery quickly (at a 10 amp rate) and stop cycling through the stages too quickly (battery seems to be holding its charge too).

My EDC module failed once before (coincidentally 4 years ago, also after a battery change - very odd). The dealership pulled the same codes and replaced/coded a new module (P/N 37-15-6-788-790).

I have a few questions I'd appreciate help with:

1) Does anyone agree/disagree agree with my diagnosis? Should I go through the trouble of measuring current draw at the battery?

2) EDC replacement seems straightforward. Remove old module and replace with a new one. Then program the new module. Does anyone know what is being programmed (ZCP programming, or only coding to VIN)?

3) Is there any downside to me replacing the EDC module with a new one (from FCP for the lifetime guarantee), driving the car to the dealer, and then having them program it? In other words, will plugging the module in and driving the car before programming cause any damage/issues with the EDC module?

4) Should I check anything else (running voltage is ~14)? Battery? Voltage regulator?

Thanks everyone!

P/S - the shop that did the battery registration also found my evaporator to be leaking ().

[BPMSport]

Disconnect the two connectors on the EDC module (white/blue) and see if the start button remains illuminated after locking the car and waiting 15 minutes. If it's no longer illuminated, the EDC module is likely your problem.

The modules are coded and also have a steering angle offset that goes above programming and coding it to your car. VIN and other data is programmed to the module. We have modules in stock in case you're interested and can program it remotely.

[rantarM3]

Thanks for your reply, Mike. I've sent you a PM.