[Asymmetric3]

Originally Posted by gbalthrop

Bentley Manual says with Engine Running, System Voltage should be in range: 13.5V to 14.5V. My N52K has always been in 14.0V to 15.0V range, per INPA/ISTA readouts.

If Bentley says 13.5-ishV is good then I'll accept it. Out of curiousity(and per your recommendation) I'm going to take my multimeter and test at other locations.

I'm NOT sure what you mean "with every misfire". Are you actually getting "Misfire" codes (P0301 - P0306), or are you just feeling RPM decrease? "Misfire" is when ONE cylinder develops LESS power on "Power Stroke" than that of cylinder Before/After it in Firing Order, resulting in measurable (by Crankshaft Sensor) slowing on that "Power Stroke". A condition that results in lack of Ignition/Power on ALL cylinders for an instant is DIFFERENT, and ususally does NOT set a "misfire" Fault Code.

I'm referring to what I call a "soft" misfire. It is a hiccup(or series of hiccups) in the engine that is most noticeable during drive idle. If I'm at a red light/stop sign and its really going at it, I'll shift to neutral which usually alleviates it. Now, this "misfire" will go from soft to hard(error code) if I accelerate hard. Then of course the check engine light appears and the car may or may not go into limp mode. A restart clears the check engine light. The scanner regularly reports a misfire on cylinders 1, 2 and "multiple cylinders". I have replaces coil packs for cylinders 1 and 2. I'm prepping to replace them all along with plugs. I haven't ruled out a ground/wiring issue as a possible cause.

ANY intermittent Interruption of Voltage Supply, either from a Loose Connection in Supply (B+) or Loose/ Failing Ground, CAN result in momentary loss of Ignition (or even DME Voltage Supply), with RPM decrease, & System Voltage decrease. If you are viewing system voltage on Instrument Cluster, using Hidden Menu 9.00, then you are likely seeing same Voltage the DME is getting from the DME Main Relay, KL87. Of course, loose DME Ground at the Nut at X6454 (On Left Strut Tower, next to Washer Filler Tube), could ALSO cause "Interruption".

My SWAG on info to date is that you have a LOOSE or Corroded connection SOMEWHERE which appears to ALWAYS cause System Voltage to be LESS than it SHOULD be, and intermittently causes RPM drop (?) with further reduction (below 13.0V?) in system voltage. That COULD be due to:
1) Loose Battery Terminals (10mm nuts on T-Bolts) either B+ or Ground;
checked & guaranteed tight!
2) Loose 13mm Nuts (under "flip-up" covers) on Rear Power Distribution Panel (RPDP) on top of battery.
checked & guaranteed tight!
3) Loose Ground Cable to Chassis at battery;
checked & guaranteed tight!
4) Loose/ Rusted/ Corroded "Transfer Points" in front of battery base;
checked & guaranteed tight!
5) Loose Ground elsewhere (e.g. X6454);
Strut tower-to-block ground replaced. Still need to replace the under chassis ground.
6) Loose B+ Supply Connection to DME.
will check

Since you first reported MULTIPLE CAS faults, and since CAS Activates the KL15 (Ignition) & KL30G (Accessory) Relays, there may also be issues in CAS Voltage Supply/ Ground, or in wiring from CAS to JB Panel to activate those relays. Still hearing any Relay Chatter from JB area?

The relay chatter disappeared after the new battery was installed. Although I think I may hear a few clicks after I turn the car off? It could just be my PTSD from months of relay chatter/no start torture. I will look into the CAS wiring.

Suggested TESTS:
1) I would BEGIN with careful measurement of Alternator output, measured at the LARGE Red B+ Cable connection to Alternator, with engine running. If that voltage value is > Voltage measured at Jumpstart Terminals under hood, or at Battery posts in boot, that is significant clue.

In the process..

2) Check that X6454 Nut (4 Brown wires from DME) is Snug.

Will check

3) If able, record & Post ALL FF Data related to EACH CAS or DME Fault now present. Clear those Codes; Run Engine until: RPM/Voltage "anomaly" recurs. Turn Engine OFF, Turn Ignition back ON & Record/ Post ALL CAS & DME Fault Codes & FF Data.

will check

4) Responding to questions in Post #13 "Wouldn't Hurt".

Which questions? For some reason there are no numbers attached to my posts/replies!

Those tests will allow us to suggest "Next Steps".
George

Edited.

[Fredo]

This is post #13:

https://www.e90post.com/forums/showp...1&postcount=13

[Asymmetric3]

Originally Posted by gbalthrop

Questions:
1) What are Last-7 Characters of your VIN?
2) Is the Creator 310+ Scan Tool shown in your photos your only Scan Tool?
Do you have the Manual for Scan Tool?.
3) Any diagnostic software such as INPA/ISTA?
4) If you have either INPA or ISTA, I can tell you HOW to diagnose the issue. If you have Creator 310+, need to know how many pages in the Manual?
5) Can your Scan Tool display "Freeze Frame Data" -- a Snapshot of system conditions at moment Fault Code saved? Think of it as "Fault Details" that offer "Clues" to nature of Fault.
6) Can your Scan Tool display "Live Data"? Such as CAS Module "Terminal Status"?
INPA/ISTA can display "Terminal Voltage" at each stage of Key insertion, Ignition ON, Starter Solenoid Activation. That is FIRST Step in Diagnosing any CAS issue, & YOU have CAS ISSUES.
7) When "intermittent start issue" occurs, does Starter Crank/Turn engine? How many places does Clicking come from: CAS, JB Panel, Starter Solenoid?
8) Do you have a Multimeter, & know how to measure DC Volts? Continuity (Ohms)?

DON'T STRESS -- DIAGNOSE. We can help & suggest Next Steps if you answer questions above.
George

Roughly a week after replacing the battery, the rain has gone and the temps are back up the the 90's.. The relay chatter has returned. My last trip back from BK(15 min total) and the IC started glitching then lit up with a fury. This time a new error(airbag)which did not clear with the others. I got home turned the car off and only the IC stayed lit. There was plenty of relay chatter and the the car did not want to start because of it. I tried again. The car started. the IC was working properly. The airbag error was gone. I turned the car off and everything turned off normally.

I have the car up on ramps now so I can replace the ground cable underneath. With this being my only vehicle, I feel like if I don't figure this out, it's going to progress and I'm going to end up getting stranded somewhere.

I'm familiar with the K15(intergrated) and 30(removable) relays. Last year I pulled the 30 and the chattter continued. I guess that means its the built-in relay.
Okay. Let me answer these..


1. A444375
2. Yes. I still have the manual and the carry bag it came with
3. I do not. But, I think its time to download it and order the connectors.
4. My Creator C310+ has a 26-page manual.
5. I don't see that option in the manual.
6. It has a "Read Datastream" option.
7. The clicking ONLY comes from the glovebox. It is the clicking that interrupts the start process. The starter actually attempts to start the engine "in-between clicks"! If there is a pause in the clicks, the engine turns over strongly and immediately.
8. I'm pretty decent with my multimeter. Running voltage at the battery is 14+ volts. Slightly higher than what the instrument cluster menu reads.

[Asymmetric3]

Update:
Instrument cluster glitch as progressed to full vehicle shutdown. That’s right! I was on my way to pick up my daughter yesterday morning and the car turned off twice immediately after the IC glitch. I was able to restart the car both times and make it make home. The car has now become unreliable!

I feel like a bit of a fool for removing the lower ground strap. It really doesn’t look that bad at all! But.. I figured since I’m going full HAM on this electrical issue, I might as well replace anything that could play a factor.

Opinions on doubling up on these lesser replacements(heat shrink or ziptied)? Even as a pair they are not as robust as the oem unit. I know they will work. But..

FYI: I found it much easier to access the top strap bolt from above with a short extension. I broke it loose with my right hand and unscrewed it with my left hand.

Next is the voltage regulator. After that, I’m pulling and inspecting the RDC and possibly the CAS.

[Asymmetric3]

UPDATE:
A few weeks ago, my 328i was dead in the the driveway with a no crank, no start. After performing a basic continuity test to the starter, I went ahead and tackled the stater replacement job. It took me about three hours. But, was successful!

More importantly, all - and I do mean ALL of the electrical issues that I had been tortured by over the last year and a half were resolved with the new starter.

Apparently, a slowly dying starter can cause all kinds of electrical issues - especially since it is connected to the alternator.

My game plan was to test and replace parts starting with the least expensive.

I replaced the battery under warranty. I replace both earth/ground straps, replaced the 30a accessory fuse, sent the "bricked" FRM module off for repair. My next step was going to be to send the CAS/keys off for testing and/or repair but luckily that wasn't necessary.

I am SO relieved to have my machine back on the road! I've suffered so long, my hand still shakes a little when I reach for the start button!

Thanks to everyone who offered their input and sypathies!