[kanman64]

Additional Details noted in previous thread in wrong forum section:

The battery compartment does show signs of corrosion, but this was apparent well before this issue started up. As it was noted when battery was replaced in 2021.

We also do have the updated B+ cable with the click on contact end.

Good day everyone,

To be upfront, I am at my wits end with my 2009 335. So for a year and a half we have been chasing an electrical failure that caused the whole car to be dead, no interior lights, no dash lights and car would stall.

Initially at first we believed a bad CAS module was at fault and we had planned to clone a new one in as the mechanic believed it was the issue at fault due to CAS codes A01C and A0B4. I had to have it done at a different shop to my original tech passing away, with the new CAS in we didn’t have any issues for a week, but then the issue came back, ABS and DSC light would flash with the cluster going blank and the radio shutting off and back to no power. After purchasing an Autel so we could read our voltage in real time as we drove we saw consistent drops while idling and driving to under 12V so we had the alternator rebuilt with OEM Bosch internals, we have confirmed the rebuilt unit is charging the battery as we can see the SOC (State of Charge) getting to 100% almost everyday. However the issue remained, after reading up we came to the conclusion that our B+ cable and fusebox were at fault due to codes 2AB4 and 2DEC for power management. I replaced the main cable and fusebox and these codes have since cleared and to my knowledge have stayed cleared.

Now come to two days ago, I’m driving home and the cluster goes blank and DSC and ABS lights flash again and the car dies in the highway but comes back to life immediately. I turn off the radio and turn off the vents and AC and car makes it home no issue. My wife goes to start it in the morning, it powers up and immediately goes dead.

I know have High Voltage Codes stored in the ABS module but nothing in the DME in regards to voltage or power issues.

I am stuck as this car has been to three shops trying to figure this out and am at my breaking point mostly.

Any help would be appreciated.

[gbalthrop]

Originally Posted by kanman64

... 2009 335i [E92]... I’m driving home and the cluster goes blank and DSC and ABS lights flash again and the car dies in the highway but comes back to life immediately. I turn off the radio and turn off the vents and AC and car makes it home no issue. My wife goes to start it in the morning, it powers up and immediately goes dead.
I know have High Voltage Codes stored in the ABS module but nothing in the DME in regards to voltage or power issues...

Questions:
1) What are Last-7 Characters of VIN?
2) What Make/Model Scan Tool or Diagnostic Software (INPA/ISTA) do you have?
2a) List ALL Fault Codes in ALL Modules.
2b) Can your Scan Tool Display Freeze Frame Data?
2c) Can your Scan Tool Display Live Data?
3) Define "goes dead" as used to describe what car did: stalls but restarts; No Instrument Cluster Lights? No Crank? Crank but NO Start?
4) Do you have a Multimeter?
5) Current Status as far as Starter Crank, Crank NO Start, Instrument Panel & interior lights, etc.

With answers to those questions we can suggest "Next Steps".
George

[kanman64]

Originally Posted by gbalthrop

Questions:
1) What are Last-7 Characters of VIN?
2) What Make/Model Scan Tool or Diagnostic Software (INPA/ISTA) do you have?
2a) List ALL Fault Codes in ALL Modules.
2b) Can your Scan Tool Display Freeze Frame Data?
2c) Can your Scan Tool Display Live Data?
3) Define "goes dead" as used to describe what car did: stalls but restarts; No Instrument Cluster Lights? No Crank? Crank but NO Start?
4) Do you have a Multimeter?
5) Current Status as far as Starter Crank, Crank NO Start, Instrument Panel & interior lights, etc.

With answers to those questions we can suggest "Next Steps".
George

Hi George,

Last 7 is P047814, I’m currently running an Autel MX808, the tool does offer freeze frame data, but when viewing the High Voltage Codes in the ABS it doesn’t show a system voltage at the time of occurrence, only the amount of times the fault occurred. It also does do live data, which I’ve used to diag other issues on the car, mainly bad fuel pump. Now for “goes dead” means we lose all electrical power to the vehicle and have to hookup a jumper or battery charger to get it to come back. Such as yesterdays morning when my wife went to drive it and the vehicle lost power I had to jump it to get it out of the road, after jumping it, I was able to turn the vehicle off and it had electrical power, go out this morning and dead again. I did notice when I went to jump the vehicle that morning, even though we had no dash lighting, no interior lighting and the key not responding, the headlight switch by driver side door was flickering showing that some system was drawing power. I’m not sure which system powers that switch (I believe CAS?) and yes I have a multimeter and a power probe which I used to verify the fusebox was getting voltage after we replaced the B+ line. Currently the car is completely dead, no interior lights, no response from key fob and nothing on instrument panel when inserting key.

I have attached pictures of the fault codes. And the current battery charge history of the last 5 days

[GSB]

Originally Posted by kanman64

Additional Details noted in previous thread in wrong forum section:

The battery compartment does show signs of corrosion, but this was apparent well before this issue started up. As it was noted when battery was replaced in 2021.

We also do have the updated B+ cable with the click on contact end.

Good day everyone,

To be upfront, I am at my wits end with my 2009 335. So for a year and a half we have been chasing an electrical failure that caused the whole car to be dead, no interior lights, no dash lights and car would stall.

Initially at first we believed a bad CAS module was at fault and we had planned to clone a new one in as the mechanic believed it was the issue at fault due to CAS codes A01C and A0B4. I had to have it done at a different shop to my original tech passing away, with the new CAS in we didn’t have any issues for a week, but then the issue came back, ABS and DSC light would flash with the cluster going blank and the radio shutting off and back to no power. After purchasing an Autel so we could read our voltage in real time as we drove we saw consistent drops while idling and driving to under 12V so we had the alternator rebuilt with OEM Bosch internals, we have confirmed the rebuilt unit is charging the battery as we can see the SOC (State of Charge) getting to 100% almost everyday. However the issue remained, after reading up we came to the conclusion that our B+ cable and fusebox were at fault due to codes 2AB4 and 2DEC for power management. I replaced the main cable and fusebox and these codes have since cleared and to my knowledge have stayed cleared.

Now come to two days ago, I’m driving home and the cluster goes blank and DSC and ABS lights flash again and the car dies in the highway but comes back to life immediately. I turn off the radio and turn off the vents and AC and car makes it home no issue. My wife goes to start it in the morning, it powers up and immediately goes dead.

I know have High Voltage Codes stored in the ABS module but nothing in the DME in regards to voltage or power issues.

I am stuck as this car has been to three shops trying to figure this out and am at my breaking point mostly.

Any help would be appreciated.

Very frustrating. It could be any number of things. You'd need to monitor your battery voltage full-time to see if the battery, battery connections or battery management systems are failing.

2DEC:
Power management, battery control
Sometimes appears when removing battery cable
Reconnect battery, clear and rescan

This code could indicate that the battery connections are failing somewhere. Did you have the recall done on your battery terminal/cable? Several people were suddenly stranded when this terminal started failing, and symptoms seemed intermittent, which is always frustrating. Loose connections anywhere along the 12V supply line or the grounding cables/connections can be responsible.

2AB4:
DME, internal error: RAM-checksum
Error will cause a warning light
Error is not currently present
Test conditions have been completed
Short circuit or signal interruption

This problem MAY be due to the previous fault condition, but this code was also experienced by several people whose DME (CPU) was failing, and the symptoms were similar to yours as well. Check the huge multi-pin connectors to the DME for water or oil infiltration (which may seem unlikely, but it's happened! Oil has migrated through the wiring from one of the sensors that became saturated with oil). Try reseating those DME connectors, and inspect them carefully.

I got rain inside my DME, and it freaked out badly. I was able to resurrect the DME, here: DIY: How to Save Your Electronics After Water Infiltration or Contamination

[GSB]

Originally Posted by kanman64

Hi George,

Last 7 is P047814, I’m currently running an Autel MX808, the tool does offer freeze frame data, but when viewing the High Voltage Codes in the ABS it doesn’t show a system voltage at the time of occurrence, only the amount of times the fault occurred. It also does do live data, which I’ve used to diag other issues on the car, mainly bad fuel pump. Now for “goes dead” means we lose all electrical power to the vehicle and have to hookup a jumper or battery charger to get it to come back. Such as yesterdays morning when my wife went to drive it and the vehicle lost power I had to jump it to get it out of the road, after jumping it, I was able to turn the vehicle off and it had electrical power, go out this morning and dead again. I did notice when I went to jump the vehicle that morning, even though we had no dash lighting, no interior lighting and the key not responding, the headlight switch by driver side door was flickering showing that some system was drawing power. I’m not sure which system powers that switch (I believe CAS?) and yes I have a multimeter and a power probe which I used to verify the fusebox was getting voltage after we replaced the B+ line. Currently the car is completely dead, no interior lights, no response from key fob and nothing on instrument panel when inserting key.

I have attached pictures of the fault codes. And the current battery charge history of the last 5 days

You now have a plethora of other codes going on, and power problems can trigger those too. If it was only the codes you show in your last post, I'd be chasing different causes.

[kanman64]

Originally Posted by GSB

Very frustrating. It could be any number of things. You'd need to monitor your battery voltage full-time to see if the battery, battery connections or battery management systems are failing.

2DEC:
Power management, battery control
Sometimes appears when removing battery cable
Reconnect battery, clear and rescan

This code could indicate that the battery connections could be failing somewhere. Did you have the recall done on your battery terminal/cable? Several people were suddenly stranded when this terminal started failing, and symptoms seemed intermittent, which is always frustrating. Loose connections anywhere along the 12V supply line or the grounding cables/connections can be responsible.

2AB4:
DME, internal error: RAM-checksum
Error will cause a warning light
Error is not currently present
Test conditions have been completed
Short circuit or signal interruption

This problem MAY be due to the previous fault condition, but this code was also experienced by several people whose DME (CPU) was failing, and the symptoms were similar to yours as well. Check the huge multi-pin connectors to the DME for water or oil infiltration (which may seem unlikely, but it's happened! Oil has migrated through the wiring from one of the sensors that became saturated with oil). Try reseating those DME connectors, and inspect them carefully.

I got rain inside my DME, and it freaked out badly. I was able to resurrect the DME, here: DIY: How to Save Your Electronics After Water Infiltration or Contamination

Both the codes you just mentioned were present before we replaced the B+ cable and the fusebox and have so far not came back (or weren’t present when I scanned the car two days ago.)

[GSB]

Originally Posted by kanman64

Now come to two days ago, I’m driving home and the cluster goes blank and DSC and ABS lights flash again and the car dies in the highway but comes back to life immediately. I turn off the radio and turn off the vents and AC and car makes it home no issue. My wife goes to start it in the morning, it powers up and immediately goes dead.

But this is what would concern me... You still have power drop-outs going on.

[GSB]

Just for interest, check out this video on the IBS sensor too...

[GSB]

Also read this experience... I almost die- "2DEC" Fault Code -Voltage Issue - Loose Wire/Connection on Junction Box. Battery terminal recall had been done but a loose B+ connection was found behind the junction box.

[kanman64]

Originally Posted by GSB

But this is what would concern me... You still have power drop-outs going on.

Yes, and this has been a year and a half of chasing and replacing things that seemed obvious but have clearly eluded me and three other techs.

[GSB]

Originally Posted by kanman64

Yes, and this has been a year and a half of chasing and replacing things that seemed obvious but have clearly eluded me and three other techs.

Right. Your experience is not at all different than this one... Another identical intermittent issue. It gets more interesting on page 2,3...
Complete Electrical Power Loss (Service Bulletin)

[kanman64]

Originally Posted by GSB

Right. Your experience is not at all different than this one... Another identical intermittent issue. It gets more interesting on page 2,3...
Complete Electrical Power Loss (Service Bulletin)

Unfortunately the repair you have linked has already been performed with the updated part number and all bolts on the Power Distribution Box are torqued to spec.

[GSB]

Originally Posted by kanman64

Unfortunately the repair you have linked has already been performed with the updated part number and all bolts on the Power Distribution Box are torqued to spec.

Yeah, but some of the guys on this forum (and in that thread) had the same repair done, yet the problem persisted because it was only partially completed, or wasn't completed properly. I would still be very skeptical, considering your complete power loss issues are still occurring. There could well be other issues, but a power loss can trigger many other codes.
The DME is another concern.

[kanman64]

Originally Posted by GSB

Yeah, but some of the guys on this forum (and in that thread) had the same repair done, yet the problem persisted because it was only partially completed, or wasn't completed properly. I would still be very skeptical, considering your complete power loss issues are still occurring. There could well be other issues, but a power loss can trigger many other codes.
The DME is another concern.

I believe this fault lies in the ABS. As our fusebox connection is solid as when the car died on my wife I did wiggle the box around and saw no change in the state. Our battery is reading 5 volts so something is severely draining this battery. I believe it to be the CAS but I wanted more opinions here as the Master Techs here in ATL believe we will need to replace both the CAS and DME or that our voltage regulator may be the fault, but I will have to load the system tomorrow morning to see if we get above 13.7 volts or if goes to 14.5 or higher.

[GSB]

Yikes, 5V is REALLY bad. Below about 10-11V some very strange things happen to the electronics in this car. One more thing to try before replacing modules, is to unplug those modules one at a time while the car is standing to see if the drain persists. The first module to try, would be the IBS. Disconnect the blue connector on the IBS, and see if the battery drain persists. FYI, the IBS, the water pump and the alternator are connected on the same bus, and if one of them goes bad, it can take them all down.

[GSB]

You can pull the fuse for some of your suspected modules too.

[gbalthrop]

Originally Posted by kanman64

... P047814... Autel MX808, the tool does offer freeze frame data, but when viewing the High Voltage Codes in the ABS it doesn’t show a system voltage at the time of occurrence, only the amount of times the fault occurred. It also does do live data...“goes dead” means we lose all electrical power to the vehicle [??] and have to hookup a jumper or battery charger to get it to come back. Such as yesterdays morning when my wife went to drive it and the vehicle lost power I had to jump it to get it out of the road, after jumping it, I was able to turn the vehicle off and it had electrical power, go out this morning and dead again. I did notice when I went to jump the vehicle that morning, even though we had no dash lighting, no interior lighting and the key not responding, the headlight switch by driver side door was flickering showing that some system was drawing power. I’m not sure which system powers that switch (I believe CAS?) and yes I have a multimeter...

Originally Posted by kanman64

I believe this fault lies in the ABS. As our fusebox connection is solid as when the car died on my wife I did wiggle the box around and saw no change in the state. Our battery is reading 5 volts so something is severely draining this battery. I believe it to be the CAS...

It is QUITE Possible that there is a SIMPLE, relatively CHEAP "Fix" for your issue. The Fact that THREE (3) $hops have "tried to figure this out" suggests the need to "Start Over" with the Basics, as assumptions have been made, and/or the "Cause" of your current issue(s) are related to something done in "Fixing" something else.

The Fault Codes you list provide NO direct clues as to WHY there is a "loss of ALL electrical power to the vehicle". The "5DF7" Code suggests "Over-voltage", or System Voltage > 16.0 V at some point. FF data should indicate how MANY times, & at what mileage, that fault occurred, at least for last 3 instances of fault. If it does NOT show exact System Voltage at moment fault code was saved, perhaps "D373" FF Data shows that parameter, as Over-Voltage tends to "Scramble" bus communications. In ANY event, 5DF7 suggests Over-voltage which CAN damage your battery, and may ALSO be associated with diode (electrical "Check-valve") failure, causing rapid battery drain.

VOLTAGE Supply Cables & Measurement:
To approach this "From Scratch", with NO ASSumptions/ ALL NEW DATA:

0) Take one or more photos of your RPDP (Rear Power Distribution Panel on top of battery), and attach it here. See NEXT Post for attachment of photo of RPDP of my 3/2007 build 328xi. Yours will likely Differ. Note that there are THREE (3) DIFFERENT B+ or Voltage Supply Cables that run to Different places on the vehicle. You need to be able to test EACH of those 3 Voltage Supply B+ cables, both at Battery/ RPDP and at "destination" end of Cable, such as at Jumpstart Terminal, or X13020 at right of JB Fuse Panel. Plan easiest way to do that. ISTA ScreenPrints for your 2009 335i E92 are attached to NEXT Post to assist in identification.

1) Disconnect Battery (-) Terminal/Cable and measure/Record Voltage at Battery Posts. Disconnect battery (+) Terminal & RPDP (Rear Power Distribution Panel) on top of battery, AFTER taking photo(s) of ALL connections to RPDP; Remove Battery from Battery Well.

1a) Inspect Battery Well for water or battery acid. Open black plastic covers of "Transfer Points" at bottom-front of well. Inspect Transfer Points for rust/corrosion. Inspect Battery case for CONVEX/ bulging sides.

2) Charge Battery at 6-Amp or 10-Amp Rate for several hours, until Battery Voltage is > 12.5 V, measured 15 minutes AFTER disconnecting Charger (when Surface Charge has dissipated). Record that voltage value. Check/ record voltage at battery Posts AGAIN 12 hours later. Battery (-) Terminal REMAINS disconnected. This is a test of ONLY the battery, to see if it maintains its charge (with ~ .1V) for 12 hours. During/ following Charging (while you wait) you can do following:

3) With battery disconnected, use Multimeter, Ohms/Resistance selected, 200 Ohms or minimum Setting, to measure resistance between Positive Terminal & Negative Terminal.

4) You can also test the fusible links in RPDP while you wait for battery voltage tests.

If the PURPOSE of each of the suggested tests/ inspections is NOT clear, please ask questions or make suggestions. The FIRST steps are to test battery, test for Resistance between Battery terminals for parasitic draw, inspect Transfer Points & Battery Well, and identify the three B+ Cables, their Function, and HOW to test each.

If you have, or can Borrow, a "Clamp Meter" that can read DC Amps/ Current, that will assist in determining which of the 3 B+ Cables (such as large one going to Jumpstart Terminal & Alternator) is carrying "Parasitic Draw Current". If you want to invest in such a tool, here is example of cheapest available AFAIK. Since "I'm Cheap", I have/ use one of these:
https://www.amazon.com/s?k=clamp+met...s_ts-doa-p_2_7
Note that some cheaper models can ONLY read AC Current/ Amps. You need to be able to read DC Current/ Amps using the CLAMP.
George

[gbalthrop]

Attached are Photos/ ScreenPrints discussed in Prior Post.
George

[gbalthrop]

Since your 335i does NOT have Valvetronic (VVT) like my 328xi, I attach what I "BELIEVE" to be the wiring diagram
for the SMALL B+ Cable, next to Inboard side of RPDP. AFAIK, that Small B+ cable runs from X1984 to F07 in E-box & water pump,
as shown in attached ISTA ScreenPrints. Appreciate comment from someone familiar with N54 Power Supply.
George

[GSB]

Originally Posted by gbalthrop

Since your 335i does NOT have Valvetronic (VVT) like my 328xi, I attach what I "BELIEVE" to be the wiring diagram
for the SMALL B+ Cable, next to Inboard side of RPDP. AFAIK, that Small B+ cable runs from X1984 to F07 in E-box & water pump,
as shown in attached ISTA ScreenPrints. Appreciate comment from someone familiar with N54 Power Supply.
George

Looks right to me. Amazing info, as always!