[rwizzle]

I have posted about this a few times, and CTUNA was kind enough to let me know that I was posting to the wrong place... Hopefully this gets a little bit of attention. Thanks in advance for your help!

car is a 2007 BMW 328xi N51 engine code - VIN last 7 is KP34057

I will say that I am new to BMW diagnostics and ISTA/d and /p software, but a quick study. I have been searching for help with this one particular issue that I just can't seem to find or solve on my own.

I have a 2007 BMW 328xi that I purchased. It was not running, cranking just fine once the battery was fully charged. I was able to run ISTA D and get into the codes, and by reviewing some older threads and the wiring diagram, I as able to find and test voltage and ground at the EKPS module. I have voltage, and ground, and have tested ground to a ground continuity. I ended up jumping the voltage supply to the fuel pump, and low and behold, the pump is now working. So.... the car runs, but still no communication with the EKPS module.

I am trying to go one step at a time, and solve the largest problems first, and I am thinking the EKPS is the largest problem as of right now, so...

Can anyone give me clear direction as to what could be happening, and what I could be testing? For example, is there a speific voltage, resistance etc I should see? I did find that I should have a 60 ohm resistance across the CAN bus lines, but when I go to check this at the OBD2 port, I don't have a pin 14 and 6...

I attached the fault codes listed. Also here is a pic of the control unit tree.

NOTE: When I bought the car, I was told that the drain lines were plugged. I can see water on the drivers side. I vacuumed a lot of water out of the carpet, and I am leaving the car in the garage with heat and windows down to dry it out... I am sure this is not good... hopefully this is common - I have seen this issue posted about but not specific to my issue.

Other posts:
https://www.bimmerpost.com/forums/sh...php?p=31828314
https://www.e90post.com/forums/showthread.php?t=2162982

Thanks again for any help in advance!

RW

[gbalthrop]

Originally Posted by rwizzle

... 2007 BMW 328xi N51 engine code - VIN last 7 is KP34057; not running, cranking just fine... test voltage
and ground at the EKPS module: I have voltage, and ground, and have tested ground to a ground continuity. I ended
up jumping the voltage supply to the fuel pump, and low and behold, the pump is now working. So.... the car runs
[with Pump Hot-wired?], but still no communication with the EKPS module...RW

Welcome to the Forum RW!
I understand you want to focus on the lack of EKPS communication. ISTA shows EKPS in RED, meaning NO Communication.
S0098, No Communication with EKPS states same. Your INPA Screens both show NO "17 EKPS" between "12 DME" & "18 EGS".
The possible causes of NO Communication with EKPS:
1) Lack of Voltage Supply (you state you have voltage: 12V+ at X13663/1, Red/Black wire, F40 OK?)
2) Lack of Chassis Ground (you state you have continuity to Chassis Ground, at X13663/2, Brown wire?)
3) Lack of Bus Communication, here via PT-CAN Bus, X13663/9, Blue/Red wire, & X13663/16, Red wire.
4) Of course, if all 3 above test OK, that suggests an internal issue with the EKPS Module itself.

Since your reported tests show that you have Voltage Supply & Chassis Ground at X13663 (?), and the Pump runs
when "Hot-wired" (12V+ to X3507/4 & Chassis Ground to X3507/2), then all that remains (retest above if any doubts) is to:

1) visually inspect Pins & Sockets at PT-CAN wires (Blue/Red & Red) X13663/9 & X13663/16. Look for any corrosion
or damage to pins/ sockets, or visible wiring.

2) Test for Voltage, in reference to Chassis Ground, Ignition ON, of the two PT-CAN wires above: X13663/9 X13663/16.

3) If you are able to get "17 EKPS" to appear on INPA > Functional Jobs > F2 Identification, or ISTA Control Unit Tree, then
use either INPA or ISTA to activate the Fuel Pump after connecting to the DME.
George

[rwizzle]

Thanks for the reply and guidance George. I will re-test to be certain before I proceed and let you know if anything was incorrect.

Question - I ASSume there should be no voltage to X13663/1 when ignition is off and key is out of ignition… One thing I noticed last night (context here - vehicle is on battery charger/tender) that WITHOUT the car on, no key in ignition, completely locked and had been so for a few hours at least, I could hear the fuel pump whining slightly. To confirm this, I pulled the fuse for the fuel pump circuit and it stopped.

2) Test for Voltage, in reference to Chassis Ground, Ignition ON, of the two PT-CAN wires above: X13663/9 X13663/16.

- to make sure I’m clear I should be testing for voltage at each PT Can wire X13663/9 and X13663/16 at the connector with negative lead touching chassis ground (X13663/2) with Ignition ON. What should voltage be for this test? ASSuming 12V…

Thanks again. Sorry for asking what seems obvious - I just like to be thorough and test once rather than repeat.

[gbalthrop]

Originally Posted by rwizzle

... I ASSume there should be no voltage to X13663/1 when ignition is off and key is out of ignition… [F40 is powered DIRECTLY by the Battery, Terminal 30, UN-switched (note the "30" above fuse symbol. So there SHOULD be battery voltage at X13663/1 unless battery terminal disconnected.] One thing I noticed last night (context here - vehicle is on battery charger/tender) that WITHOUT the car on, no key in ignition, completely locked and had been so for a few hours at least, I could hear the fuel pump whining slightly. To confirm this, I pulled the fuse for the fuel pump circuit and it stopped. [Depending upon WHERE/HOW the charger is connected, that should NOT be a factor, but you might clarify by testing to see if SAME occurs w/o charger attached. If NOT, then where/how is charger connected?]
- to make sure I’m clear I should be testing for voltage at each PT Can wire X13663/9 and X13663/16 at the connector with negative lead touching chassis ground (X13663/2) with Ignition ON. What should voltage be for this test? ASSuming 12V…

In answer to your last question: I DON'T know. I assume there should be SOME measurable voltage in each, based upon other's test reports, but I have personally never had reason to test. Reports on Forums suggest there should be some voltage in each, with PT-CAN High voltage differing from PT-CAN Low. If there is measurable voltage, that at least indicates SOME wiring continuity.

To my limited understanding/concepts, if other Modules on PT-CAN are communicating (which "Tree" shows they are), then issue of EKPS NOT communicating appears local to EKPS, or its connector. You might check ISTA for an FUB or FTD regarding BUS testing. I have NOT found anything definitive. You might also try using ISTA Test Plan on S0098 Fault Code. I've never had an "S" code, so don't know if ISTA Test Plan can function on that Code.

I'm a retired lawyer who learned wiring diagrams well before early 90's advent of CAN-Bus in autos. Never took a training course in Bus systems, & have complete lack of understanding of Geek-Speak.

So my approach is to first eliminate the simple Supply/Ground possibilities, examine the Sockets & Pins of Connector, particularly PT-CAN pins, & you might also check the 15WUP X13663/13 Green/Red wire. My understanding/ concept is that "Wakes Up"/initiates the PT-CAN Bus communication, when CAS activates KL15/Ignition.

ANYONE with different/better concepts/ knowledge of PT-CAN bus system on E9x models, please enlighten us.
George

[ctuna]

A common problem with N51 fuel tanks is the internal hoses self disassemble.
Seems like you should take care of all the Ista comm problems first .
What is your battery voltage?
How far underwater was this car?

[rwizzle]

Update - Tested for voltage with Ignition ON at X13669/9 and 13669/16 and get roughly 2.5V

My understanding/ concept is that "Wakes Up"/initiates the PT-CAN Bus communication, when CAS activates KL15/Ignition

Should this be a 12V signal with Ignition ON? I believe that is what I see in the diagram...

A common problem with N51 fuel tanks is the internal hoses self disassemble.

Can you explain this a bit further?

What is your battery voltage?

It is fully charged at 14.5V

I took the car out today - started right up. No issues at all besides all the lights flashing at me on the dash and the check engine light.... Drove it on the freeway, and didn't have any hesitation or stutter. I am going to drive it again this weekend, and see what happens. I am very confused on how I am able to drive the car with a NO COMM EPKS. I will connect back up to ISTA D tomorrwo after another drive cycle, and see what codes we have stored...

Stay tuned. Thanks for the input guys.

RW

[gbalthrop]

Originally Posted by rwizzle

Update - Tested for voltage with Ignition ON at X13663/9 and 13663/16 and get roughly 2.5V [PT-CAN High & Low wires]...
I took the car out today - started right up. No issues at all besides all the lights flashing at me on the dash and the check engine light.... Drove it on the freeway, and didn't have any hesitation or stutter. I am going to drive it again this weekend, and see what happens. I am very confused on how I am able to drive the car with a NO COMM EPKS. I will connect back up to ISTA D tomorrow after another drive cycle, and see what codes we have stored...

If your pump RUNS (& engine starts/runs), even though there is NO communication with EKPS, you should HEAR the pump running. How long does pump run/hum after Engine OFF & Remote Key removed from Insert Compartment? I have NO clue why the EKPS is sending voltage/ground signals to pump, causing Pump to run, even though NO Communication with EKPS.

I don't remember if you ever tried to activate EKP via DME using INPA or NOT. Try INPA > DME > F6 Activations > F1 > F7 Activation EKP. I'll attach ScreenPrint of that INPA Screen to NEXT Post. That screen can be used to OBSERVE pump speed as a % of Max Speed, WITHOUT over-riding DME control (don't press F1). You are using "activation" screen as an F5 Status Screen where you simply observe function under DME Control.

At idle, % speed should be in range of 20 to 25% of max speed. If your Pump Module won't communicate, you may get NO % value, even though pump & engine is running. If that is the case, it would appear to me that either:
1) you have NO PT-CAN communication with EKPS, or
2) the EKPS Module is faulty.

The key MAY be WHEN does the Pump Run? When does it shut off? Does it Run as soon as you unlock or open door? Before you Insert Key? Does it EVER shut off?

Here is a link to post regarding PT-CAN test with Multimeter and ALSO with Oscilloscope. Apparently ALL you can do with Multimeter is determine wire continuity, as both Hi & Low are same voltage. NOT sure what causes PT-CAN signal to go "Active": Ignition on? 15WUP signal? Other?
https://www.e90post.com/forums/showp...8&postcount=21
George

[gbalthrop]

INPA > DME (MSV80) > F6 > F1 > F7 EKPS Activation, simply observing as Pump under DME Control, N52K 3/2007 328xi,
engine at idle, pump at 19.5% of Max Speed, per prior post.
George

[ctuna]

14.5 better be your alternator voltage or the laws of physics have been violated, and that is sorta on the high side for and alternator . battery voltage should be around 12.6


there are many threads on the N51 gas tank problems here.

[rwizzle]

Originally Posted by gbalthrop

If your pump RUNS (& engine starts/runs), even though there is NO communication with EKPS, you should HEAR the pump running. How long does pump run/hum after Engine OFF & Remote Key removed from Insert Compartment? I have NO clue why the EKPS is sending voltage/ground signals to pump, causing Pump to run, even though NO Communication with EKPS.

I don't remember if you ever tried to activate EKP via DME using INPA or NOT. Try INPA > DME > F6 Activations > F1 > F7 Activation EKP. I'll attach ScreenPrint of that INPA Screen to NEXT Post. That screen can be used to OBSERVE pump speed as a % of Max Speed, WITHOUT over-riding DME control (don't press F1). You are using "activation" screen as an F5 Status Screen where you simply observe function under DME Control.

At idle, % speed should be in range of 20 to 25% of max speed. If your Pump Module won't communicate, you may get NO % value, even though pump & engine is running. If that is the case, it would appear to me that either:
1) you have NO PT-CAN communication with EKPS, or
2) the EKPS Module is faulty.

The key MAY be WHEN does the Pump Run? When does it shut off? Does it Run as soon as you unlock or open door? Before you Insert Key? Does it EVER shut off?

Here is a link to post regarding PT-CAN test with Multimeter and ALSO with Oscilloscope. Apparently ALL you can do with Multimeter is determine wire continuity, as both Hi & Low are same voltage. NOT sure what causes PT-CAN signal to go "Active": Ignition on? 15WUP signal? Other?
https://www.e90post.com/forums/showp...8&postcount=21
George

I can't find the screen you mention - see screenshot.

When I unlock the car, the fuel pump come ON - I can hear it running - verified current draw ~ 15A. If I lock the car, and come back to it 5 minutes later, it is OFF and I cannot hear it. Verified by looking at current draw < 1A.

[rwizzle]

Originally Posted by ctuna

14.5 better be your alternator voltage or the laws of physics have been violated, and that is sorta on the high side for and alternator . battery voltage should be around 12.6

My fault. You are correct. Verified 12.5V with Ignition OFF.

there are many threads on the N51 gas tank problems here.

I was just wondering if the disassembling you refer to would cause an issue with the pump EKPS communication - I will take a look at threads. thanks!

RW

[rwizzle]

Originally Posted by rwizzle

I can't find the screen you mention - see screenshot.

When I unlock the car, the fuel pump come ON - I can hear it running - verified current draw ~ 15A. If I lock the car, and come back to it 5 minutes later, it is OFF and I cannot hear it. Verified by looking at current draw < 1A.

One thing I noticed - I navigate in INPA > E90 > Engine > Fuel Pump EKP and when I press enter, the Fuel Pump shuts off immediately, and then I get an Error on the screen - NO RESPONSE FROM CONTROLUNIT

[gbalthrop]

Originally Posted by rwizzle

I can't find the screen you mention - see screenshot.
When I unlock the car, the fuel pump come ON - I can hear it running - verified current draw ~ 15A. If I lock the car, and come back to it 5 minutes later, it is OFF and I cannot hear it. Verified by looking at current draw < 1A.

See the attached pdf, INPA Tutorial Quickstart. It doesn't contain exact instructions of HOW to access the screen in question, but on page 3, it shows the Opening Screen & Script Selection Box which appears after you select "E90" or 3 series, which is < F8 > on your particular INPA version. After you press F8, or click on that button on the Status Bar, the Listbox will appear. There, select "Engine" in Left Listbox & N52K (MSV80) in Right Listbox.

MSV80 Main Menu (Hauptmenu) should appear.
Click on F6 Activate in Status Bar & Activations Menu should appear;
Click on F1 Activate 1 in Status Bar & Menu should appear with "F7 EKP" in Status Bar;
Click on "F7 EKP" and the desired screen should appear

Save & Post that screen:
a) with Ignition ON, prior to engine start;
b) after Engine Start, with engine at idle.

BTW, if your engine starts & runs, there is NO issue with lines inside the tank. That issue results in NO/Low fuel pressure at fuel rail (NOT your case). Your reported issue is NO communication with 17 EKPS per INPA, and RED EKPS Module on ISTA Control Unit Tree -- NO Communication with EKPS. YET, your engine starts & runs.

Please indicate if pump continues to run/hum AFTER Key removal or even after locking. You said it is NOT still running when you come back ~ 5 minutes after locking, but have NOT answered the other two questions.
George

[rwizzle]

I think I am having a larger issue than the EKPS and here is my reasoning:

I have tested with a different EKPS - plugged it in and had EKPS communications. Car started and drove (yes past tense I will get there) fine.

Parked the car, went into my house. Came out a few hours later, car won't start. I connect up and run a complete ID from ISTA, I get NO COMMUNICATION EKPS and I get a new code 00CDA6 Message (status, Electric Fuel Pump, 0x335) Faulty, receiver DME, transmitter EKP

I switched back to the old module, the new module, and even a different known good module. Nothing.

I am going to do some additional research on this new code. I also did get rid of some of the other codes to try and shorten the list. Replaced AUC sensor, fixed the air mix potentiometer in the rear seat. I haven't given up, but getting very frustrated with this EKPS fuel pump issue.

RW

[ptpending]

you need to check ekps fuse, wiring, voltages and can-bus communication

[rwizzle]

Originally Posted by ptpending

you need to check ekps fuse, wiring, voltages and can-bus communication

I have checked fuse, wiring, voltages. All seem to check out properly.

Is there a specific procedure you can point to for checking can-bus communication? I find reference in ISTA but can't figure out how to access these documents.

The following documents may be helpful to check the bus connection:

Bus systems (FUB-FUB-DAA0701FB-656135001)

Diagnosis at FlexRay (FUB-HIL-HI-610002-K08)

Check of CAN bus signal (FUB-FPA-FP-610001-K08)

[ptpending]

the simple oscillograph is required to completely diagnose can bus,
without it you can disconnectd module and check can wires for short to b+ (12+V) or short to ground conditions
when all is connected and ignition is enabled there should be +~2-3V

[rwizzle]

Originally Posted by ptpending

the simple oscillograph is required to completely diagnose can bus,
without it you can disconnectd module and check can wires for short to b+ (12+V) or short to ground conditions
when all is connected and ignition is enabled there should be +~2-3V

So that I’m doing this correctly:

Check continuity from pin X13663/9 to ground and X13663/16 to ground (can wires short to ground) and check continuity from X13663/9 and 16 to X13663/1? There should not be any shorts, correct? I did previous measure voltage with ignition ON between both X13663/9 and to ground, and X13663/15 to ground and saw ~2.5V.

[gbalthrop]

Originally Posted by rwizzle

So that I’m doing this correctly:
[1] Check continuity from pin X13663/9 to ground and X13663/16 to ground (can wires short to ground) [That much is OK -- Testing for short/continuity to Chassis Ground]

[2] and check continuity from X13663/9 and 16 to X13663/1? [X13663/1 (Red/Black wire) is 12V+ Battery Voltage UNLESS you pull fuse F40 -- Don't blow yourself up ;-)] There should not be any shorts, correct? I did previous measure voltage with ignition ON between both X13663/9 and to ground, and X13663/16 to ground and saw ~2.5V.

Your previous test showing ~ 2.5V at each PT-CAN bus wire shows there is voltage supply to those wires, as there should be, but does NOT show higher voltage in PT 'high' Blue/Red wire. An oscilloscope would show wave form. If you pull fuse F40, you can use the "Ohms/Continuity" test to determine if there is any contact between the Red/Black wire & either PT-CAN wire. NEVER use an Ohms/continuity test on a wire that MAY be powered.

One more test: test for continuity between the two PT-CAN wires. CAN bus wires are twisted pairs, & if they get pinched against sharp metal edge, there will be unwanted continuity between the Red wire & Blue/Red wire.

Probably NONE of us on the Forum use a Multimeter often enough to not have to CONCENTRATE on what we are doing & why. Just go slow & think.
George

[rwizzle]

Originally Posted by gbalthrop

Your previous test showing ~ 2.5V at each PT-CAN bus wire shows there is voltage supply to those wires, as there should be, but does NOT show higher voltage in PT 'high' Blue/Red wire. An oscilloscope would show wave form. If you pull fuse F40, you can use the "Ohms/Continuity" test to determine if there is any contact between the Red/Black wire & either PT-CAN wire. NEVER use an Ohms/continuity test on a wire that MAY be powered.

One more test: test for continuity between the two PT-CAN wires. CAN bus wires are twisted pairs, & if they get pinched against sharp metal edge, there will be unwanted continuity between the Red wire & Blue/Red wire.

Probably NONE of us on the Forum use a Multimeter often enough to not have to CONCENTRATE on what we are doing & why. Just go slow & think.
George

Here are the results of the testing:

With Fuse F40 pulled:

X13663/1 to X13663/9 - Open
X13663/1 to X13663/16 - Open
X13663/9 to X13663/16 - SHORT

So this points to a pinched wire somewhere... What would be the best way to find this. It must be between the EKP and the next item in the CAN BUS chain.

Any suggestions on what connector to start at?

Thanks so much for this help!

[gbalthrop]

Originally Posted by rwizzle

Here are the results of the testing:
With Fuse F40 pulled:
X13663/1 to X13663/9 - Open
X13663/1 to X13663/16 - Open
X13663/9 to X13663/16 - SHORT [3 tests above are with X13663 DISCONNECTED from EKPS, as opposed to Back-probing attached connector?]
So this points to a pinched wire somewhere [Perhaps NOT -- see below]... What would be the best way to find this. It must be between the EKP and the next item in the CAN BUS chain. Any suggestions on what connector to start at?...

My apologies for the distractions. As you can see, I missed your 2/8 post 'cuz I was composing my own, posted ~ 30 minutes later (yes, I'm SLOOOW ;-) Since this thread has been running for ~ 2 weeks now, I have just re-read your posts, and in an effort to get everyone on same page, here's a summary (please correct me immediately if anything incorrect or I omit something significant):

Recap of posts:
1) Vehicle: 2/2007 build 328xi, N51, AT US

2) You have both INPA & ISTA: your ScreenPrints (Post #1) show NO communication with EKPS, while you have communication with all 4 other Modules on PT-CAN bus: DME, EGS, VTG & DSC/DXC, & you have S0098 fault, NO communication with EKPS.

3) You have Battery Voltage at X13663/1 & Continuity to Chassis Ground at X13663/2 (connector at EKPS); with Ignition ON, you have ~ 2.5V at each PT-CAN wire, X13663/9 & /16.

4) The fuel pump runs when "Hot-wired" by applying 12V+ to X3507/4 & ground to X3507/2. The engine starts/ runs when fuel pump runs. What is NOT clear is whether or not "Hot-wiring" left in place, pump runs when charger connected, pump quits when F40 removed, etc. (Post #1)

5) ISTA ScreenPrints of SSP wiring diagram for EKPS on OP's vehicle were attached to Post #2.

6) Post #6 on 2/7/2025 confuses me a bit. RW states "car started right up". "Drove on freeway, no hesitation or stutter". What is NOT clear is if RW viewed ISTA "Tree" or INPA "Identification" to see if there was THEN communication with EKPS. I'm NOT aware of any "Feature" of the EKPS that defaults to pump running if NO PT-CAN communication, & that would seem completely contrary to pump shutdown when Ignition off/key removed.

7) On 2/8, you stated in Posts #10 & #12: "When I unlock the car, I can hear fuel pump running". 5 minutes after locking car, you cannot hear fuel pump.

When attempting to view INPA "Activation" Screen (DME > F6 > F1 > F7), the pump shuts off, & you get error message: "NO RESPONSE FROM CONTROL UNIT". What is NOT clear to me is what caused the pump to be running in the first place?/ was engine also running?/ did you press F1 or F2 after the screen opened (to over-ride DME Control), or did the pump shut off simply due to attempting to open that screen (attempting PT-CAN communication with EKPS)?

8) You reported on 2/16 that you "plugged in" a different EKPS & had Communication (How determined?), & car started & drove. Few hours later, "car won't start". Presumably that means Cranks, but NO Start/fire/fuel. ISTA showed NO Communication with EKPS & new Code: "CDA6 Message (status, Electric Fuel Pump, 0x335) Faulty, receiver DME, transmitter EKP". Here is link to the Fault Info sheet for that code:
https://bmwfault.codes/XMLDiagView?d...E4Nzg0NTQwNQ==

I would ASSume that there is an intermittent fault causing disruption of PT-CAN communication with the EKPS, most likely an "Open Circuit" in PT-CAN wiring at the EKPS Connector X13663, since the other 4 PT-CAN Modules can communicate via the JBE 'Hub/ Gateway'. Based upon my layman's concept of Bus Communications, a "Short" between the two PT-CAN wires would affect operation of the ENTIRE bus, & yet the other 4 modules on PT Bus communicate, even though NO communication with EKPS.

Apparently when you plugged in the first replacement EKPS, that resulted in contact of the intermittent open circuit. Yet later R&R's of the EKPS with units that have worked at other times resulted in "nothing". Does that mean NO Communication? No Fire/Start when cranked? For those of us who are SLOOOW/ pedantic/ Detail-Oriented, we need specifics.

It's easy to think that if you had a more expensive tool (such as an oscilloscope), that would somehow solve the puzzle. I don't have one, but it appears that would only confirm that there is NO correct wave pattern, OR it would at best show that there IS a wave correct wave pattern SOMEWHERE in the PT-CAN wires at some point NEAR its X13663 Connector. It appears to me that you have already established that to a high degree of certainty, with intermittent starts, starting after Module swap (Sometimes & sometimes NOT). Cheap NEXT Steps suggested:

Try:
1) Cleaning connector Sockets & original EKPS Module pins with Electronic Contact Cleaner;
2) Carefully inspecting the Sockets #1, 2, 9 & 16 to make sure they have NOT gotten enlarged/ sloppy fit; Also Check the 15WUP socket X13663/13.
3) Gently 'jiggle' or manipulate the X13663 harness/connector at the EKPS (plugged in, ignition ON, INPA Functional Jobs > F2 Identification Screen displayed), & see if "17 EKPS" appears between 12 DME & 18 EGS.
My "Bigly-educated, non-professional" opinion: Something Ain't Right in the X13663 connector, or its fit onto EKPS Pins.

If I knew a better way to locate the PT-CAN fault, I would disclose it.
Suggestions by others WELCOME!
Upon "Further Review" of my suggestion in Post #19: as stated above, my limited knowledge suggests that if the two PT-CAN wires were shorted together, that would affect ALL PT-CAN communication (Other 4 Modules).

If your test suggests there was a "short" between the two PT-CAN wires at sockets X13663/9 & X13663/16, please describe EXACTLY how that test was conducted: X13663 Connector dis-connected from EKPS? X13663 Connected to EKPS, & Back-probing the two wires? Other?
George

[rwizzle]

[3 tests above are with X13663 DISCONNECTED from EKPS, as opposed to Back-probing attached connector?]

CORRECT. Module was disconnected from the connector, and probing was done at connector pins.

Recap of posts:
1) Vehicle: 2/2007 build 328xi, N51, AT US CORRECT

2) You have both INPA & ISTA: your ScreenPrints (Post #1) show NO communication with EKPS, while you have communication with all 4 other Modules on PT-CAN bus: DME, EGS, VTG & DSC/DXC, & you have S0098 fault, NO communication with EKPS. CORRECT

3) You have Battery Voltage at X13663/1 & Continuity to Chassis Ground at X13663/2 (connector at EKPS); with Ignition ON, you have ~ 2.5V at each PT-CAN wire, X13663/9 & /16. CORRECT. THIS WAS VERIFIED TO SEPERATE GROUND, AND TO CONNECTOR GROUND (DOUBLE CHECKING X13661/2)

4) The fuel pump runs when "Hot-wired" by applying 12V+ to X3507/4 & ground to X3507/2. The engine starts/ runs when fuel pump runs. What is NOT clear is whether or not "Hot-wiring" left in place, pump runs when charger connected, pump quits when F40 removed, etc. (Post #1) HOT-WIRING WAS JUMPING 12V FROM X13661/1 TO X3507/4. I WAS ABLE TO REMOVE THIS WIRE, AND MIRACULOUSLY THE PUMP WOULD STILL FUNCTION, EVEN THOUGH I DISCONNECTED THE WIRE. THIS IS NO LONGER THE CASE, AND POINTS TO YOUR MESSAGE BELOW (FAULTY CONNECTOR/LOOSE PINS)

5) ISTA ScreenPrints of SSP wiring diagram for EKPS on OP's vehicle were attached to Post #2.

6) Post #6 on 2/7/2025 confuses me a bit. RW states "car started right up". "Drove on freeway, no hesitation or stutter". What is NOT clear is if RW viewed ISTA "Tree" or INPA "Identification" to see if there was THEN communication with EKPS. I'm NOT aware of any "Feature" of the EKPS that defaults to pump running if NO PT-CAN communication, & that would seem completely contrary to pump shutdown when Ignition off/key removed. I DID VIEW ISTA TREE AND HAD NO COMMS CODE STORED AND STILL RED ON THE TREE

7) On 2/8, you stated in Posts #10 & #12: "When I unlock the car, I can hear fuel pump running". 5 minutes after locking car, you cannot hear fuel pump. CORRECT. THIS IS NOT HAPPENING ANY LONGER

When attempting to view INPA "Activation" Screen (DME > F6 > F1 > F7), the pump shuts off, & you get error message: "NO RESPONSE FROM CONTROL UNIT". What is NOT clear to me is what caused the pump to be running in the first place?/ was engine also running?/ did you press F1 or F2 after the screen opened (to over-ride DME Control), or did the pump shut off simply due to attempting to open that screen (attempting PT-CAN communication with EKPS)? THE PUMP WAS RUNNING AS IF THE COMPUTER WAS ABLE TO WAKE IT WHEN THE DOOR WAS OPENED. WHILE THE PUMP WAS RUNNING, I CONNECTED TO ISTA/D AND SAW NO COMMS ERROR. I THEN OPENED INPA, SELECTED E90 -> ENGINE -> FUEL PUMP EKP AND THEN I BELIEVE IT GAVE ME A COMMUNICATION FAULT, AND AT THE SAME TIME AS SELECTING THE MENU (WHEN IT ATTEMPTED COMMUNICATION) THE FUEL PUMP STOPPED WHINING

8) You reported on 2/16 that you "plugged in" a different EKPS & had Communication (How determined?) ISTA/D SHOWED A GREEN MODULE, & car started & drove. Few hours later, "car won't start". Presumably that means Cranks, but NO Start/fire/fuel. ISTA showed NO Communication with EKPS & new Code: "CDA6 Message (status, Electric Fuel Pump, 0x335) Faulty, receiver DME, transmitter EKP". CORRECT Here is link to the Fault Info sheet for that code:
https://bmwfault.codes/XMLDiagView?d...E4Nzg0NTQwNQ==

I would ASSume that there is an intermittent fault causing disruption of PT-CAN communication with the EKPS, most likely an "Open Circuit" in PT-CAN wiring at the EKPS Connector X13663, since the other 4 PT-CAN Modules can communicate via the JBE 'Hub/ Gateway'. Based upon my layman's concept of Bus Communications, a "Short" between the two PT-CAN wires would affect operation of the ENTIRE bus, & yet the other 4 modules on PT Bus communicate, even though NO communication with EKPS. THIS IS A GREAT POINT. I WOULD ALSO THINK A SHORT WOULD TAKE DOWN THE ENTIRE BUS.

Apparently when you plugged in the first replacement EKPS, that resulted in contact of the intermittent open circuit. Yet later R&R's of the EKPS with units that have worked at other times resulted in "nothing". Does that mean NO Communication? No Fire/Start when cranked? For those of us who are SLOOOW/ pedantic/ Detail-Oriented, we need specifics. CORRECT. MOST OF THE TIME, I HAVE NOT BEEN ABLE TO SEE ANY COMMUNICATION USING ISTA, AND 17 EKPS WILL NOT SHOW UP IN INPA. THE CAR ALWAYS CRANKS. WHEN I WAS FIRST DIAGNOSING THIS PROBLEM, AND JUMPED THE HOT-WIRE FROM X13663/1 TO X3507/4 I WAS ABLE TO GET THE CAR TO START, AND THEN WHEN I DISCONNECTED THE HOT-WIRE, THE PUMP STAYED RUNNING, WHICH I FOUND ODD, AND ESPECIALLY WHEN I WOULD CONNECT BACK UP TO ISTA AND HAVE A NO COMM FAULT

It's easy to think that if you had a more expensive tool (such as an oscilloscope), that would somehow solve the puzzle. I don't have one, but it appears that would only confirm that there is NO correct wave pattern, OR it would at best show that there IS a wave correct wave pattern SOMEWHERE in the PT-CAN wires at some point NEAR its X13663 Connector. It appears to me that you have already established that to a high degree of certainty, with intermittent starts, starting after Module swap (Sometimes & sometimes NOT). Cheap NEXT Steps suggested:

Try:
1) Cleaning connector Sockets & original EKPS Module pins with Electronic Contact Cleaner;
2) Carefully inspecting the Sockets #1, 2, 9 & 16 to make sure they have NOT gotten enlarged/ sloppy fit; Also Check the 15WUP socket X13663/13.
3) Gently 'jiggle' or manipulate the X13663 harness/connector at the EKPS (plugged in, ignition ON, INPA Functional Jobs > F2 Identification Screen displayed), & see if "17 EKPS" appears between 12 DME & 18 EGS.
My "Bigly-educated, non-professional" opinion: Something Ain't Right in the X13663 connector, or its fit onto EKPS Pins. THE MORE I READ AND THINK ABOUT THIS THE MORE I LEAN TOWARD THIS DIAGNOSIS AS WELL. I WILL DO ABOVE AND REPORT BACK. ONE QUESTION - IF I JIGGLE THE HARNESS WHILE CONNECTED TO INPA, IS IT UPDATING IN REALTIME, OR WILL I HAVE TO CONTINUE RUNNING THE "INPA Functional Jobs > F2 Identification Screen" EACH TIME I "JIGGLE THE HARNESS"

If I knew a better way to locate the PT-CAN fault, I would disclose it.
Suggestions by others WELCOME!
Upon "Further Review" of my suggestion in Post #19: as stated above, my limited knowledge suggests that if the two PT-CAN wires were shorted together, that would affect ALL PT-CAN communication (Other 4 Modules).

If your test suggests there was a "short" between the two PT-CAN wires at sockets X13663/9 & X13663/16, please describe EXACTLY how that test was conducted: X13663 Connector dis-connected from EKPS? X13663 Connected to EKPS, & Back-probing the two wires? Other? X13663 WAS DISCONNECTED, FUSE F40 WAS REMOVED, NEGATIVE LEAD ON PIN 9, POSITIVE LEAD ON PIN 16
George

Thanks George for the thorough review. replys are above