[Yoyofatboy]

Hello all, first post here but I've read many threads since picking up my first BMW last week.

Long-story short, this abused 3 series doesn't fire. I've got fuel pressure and good compression, but not getting any spark. Connected directly to coil wiring with noid light to test, nothing on all 6.

ISTA+ diags give many codes, all for no comms with X component:
S0074 - no comms w/ CAS
S0085 - no comms w/ DSC
S0114 - no comms w/ control unit possible
S0119 - no comms w/ Ins Panel
S0129 - no comms w/ Engine Electronics
S0180 - no comms w/ Safety Restraint Sys
S0212 - no comms w/ Junction Box Electronics
S0364 - no comms w/ Trans Control
S0758 - Permanent SAE fault code

Pulled DME and saw a tiny bit of blue corrosion on the terminals, cleaned up as best I can and reinstalled. Fuse F38 (Crankcase Breather Heating/ECM/O2 Sensor) kept blowing until I unplugged the upstream o2 sensors, shorted somewhere. The rear valve cover ground was badly rusted so i connected it to a different grounding location. Verified Ground next to the DME enclosure is tight and clean. Checked all other ECM/DME related fuses, none other were blown. Battery Control Module has seen better days, but I get over 12v to the front of engine.

I've got a good multimeter, a test light, and a working ISTA+ install w/ Enet Cable.

Would anyone more versed in electronics diagnostics be able to point me in the right direction?

[NZE90]

It's not uncommon for ISTA to report no comms to various control units. The most common reason is incorrect COM port settings.

Check your COM port settings are correct and your latency time is set to 1.

[Yoyofatboy]

Originally Posted by NZE90

It's not uncommon for ISTA to report no comms to various control units. The most common reason is incorrect COM port settings.

Check your COM port settings are correct and your latency time is set to 1.

Thank you for the swift reply. I also came to the same conclusion that my ISTA was not functioning as it should. I had tried multiple installation methods from many sources and there might've been some problems inbetween.

I will be reinstalling from a fresh slate and trying to configure from there.

As a side note, my generic OBD2 scanner also read comms issues so i assumed the information received was correct. (U0001, U0100, U0401)

Will report back soon

[jadams161]

Have you checked the main body ground strap yet? It runs from the drivers side motor mount to the frame. It is a braided strap that is a complete POS and is most likely green or broken.

[Yoyofatboy]

Ordered a K+D-CAN Cable, I believe my enet setup was the problem. Could not get the networking portion working so I will try via USB.

Originally Posted by jadams161

Have you checked the main body ground strap yet? It runs from the drivers side motor mount to the frame. It is a braided strap that is a complete POS and is most likely green or broken.

Pulled the ground just now, it was dusty but no corrosion and had solid metal connections. I'll still clean up the posts but I don't believe it was at fault. I definitely didnt see that ground tho, so thanks for that suggestion.

[gbalthrop]

Originally Posted by Yoyofatboy

... this abused 3 series doesn't fire. I've got fuel pressure and good compression, but not getting any spark.
Connected directly to coil wiring with noid light to test, nothing on all 6.
ISTA+ diags give many codes, all for no comms with X component:
S0074 - no comms w/ CAS
S0085 - no comms w/ DSC
S0114 - no comms w/ control unit possible
S0119 - no comms w/ Ins Panel
S0129 - no comms w/ Engine Electronics
S0180 - no comms w/ Safety Restraint Sys
S0212 - no comms w/ Junction Box Electronics
S0364 - no comms w/ Trans Control
S0758 - Permanent SAE fault code

... Fuse F38 (Crankcase Breather Heating/ECM/O2 Sensor) kept blowing until I unplugged the upstream o2 sensors,
shorted somewhere. The rear valve cover ground was badly rusted so i connected it to a different grounding location.
Verified Ground next to the DME [X6454, Nut on Strut Tower?] enclosure is tight and clean. Checked all other
ECM/DME related fuses, none other were blown. Battery Control Module [you mean "Rear Power Distribution Panel" on
TOP of battery?] has seen better days, but I get over 12v to the front of engine. [at Jumpstart Terminals?]

I've got a good multimeter, a test light, and a working ISTA+ install w/ Enet Cable...

See attached pdf's for ways to use ISTA+ & a few issues with Setup.
There are MANY different versions of ISTA+ "out there". The version I use requires installation of working version of
"BMW Standard Tools" (INPA) BEFORE ISTA install, and TOTAL Hard-drive space of both installations is ~ 25 GB. I use
K+DCAN cable. There MAY be "Settings" to change to use ENET Cable.

It is possible to have a Functioning ISTA+ Installation for use as "Shop Manual", to see Documents while NOT connected
to vehicle. However if "VCI Config" settings in ISTA are NOT correct, that MAY prevent connecting with vehicle. If a simple
OBD II P-Code Reader can't show DME Live Data, then there is an issue with DME "communication" with JBE Hub/Gateway.

That issue could be due to:
a) Lack of Power Supply or Ground (X6454);
b) Lack of Bus (PT-CAN Bus for DME) communication;
c) Internal DME Fault.

You WILL need a functioning ISTA installation (or at least functioning INPA installation if you have BMW Standard Tools).
So I would FIRST get either INPA/ISTA working.
If ISTA:
1) Post ScreenPrints of: a) Control Unit Tree; b) Fault Memory

If INPA, Post ScreenPrints of:
1) INPA > Functional Jobs > F2 Identification, showing List of ALL Modules communicating with JBE;

2) INPA > Functional Jobs > F4 > F1 Fault Memory, ALL Modules

See this link for pdf's related to INPA:
https://www.bimmerfest.com/threads/t...#post-13810062

See attached ISTA ScreenPrints for examples of ISTA wiring diagrams. There are TWO fuses powering DME: F4 & F37.
F4 is permanent Power (KL30) and F37 is switched by DME Main Relay (KL87). Also check Ground connections at X6454.
F38 circuit is also attached, showing supply to O2 Sensor Heaters, & Crankcase Breather Heater (located under
Intake Manifold), as to which there was a Recall in 2017. If that heater shorts out, it blows F38 -- NO O2 Sensor Heating.

Please let us know what you find/ Questions.
George

[Yoyofatboy]

Thank you for all your input. I was able to get ISTA working with the DCAN cable. Attached screenshot of my Control Unit Tree. Lots of Red.

To answer a few of the inline questions and comments posed:
- X6454 Ground is good, re-cleaned and verified ground.
- Yes, Rear Power Distribution Panel is what I was referencing. It's busted in a few areas.
- +12V at Jumpstart terminals
- Body to Engine ground underneath the car has been cleaned and reinstalled.
- My upstream o2 sensors are grounded out for sure, but when disconnected I no longer blow the fuse. Issue to be tackled at a later time, car should start without them, correct?

Fault codes with working ISTA jumped to 46 total. Lots of communication errors. If helpful I can export the full list.

Since my DME is not responding, where can I probe to test? How common is a failed DME? And if I crack it open to check, how easy is that to do?

[gbalthrop]

Originally Posted by Yoyofatboy

... I was able to get ISTA working with the DCAN cable. Attached screenshot of my Control Unit Tree. Lots of Red...
- My upstream o2 sensors are grounded out for sure, but when disconnected I no longer blow the fuse. Issue to be tackled at a later time, car should start without them, correct? [see below]... Since my DME is not responding, where can I probe to test?

I'm NOT sure where/how you disconnected the O2 Sensors. Fuse F38 is the supply for the HEATERS of the 4 O2 Sensors & the Crankcase Breather. While disconnecting the O2 Sensor Connectors should NOT prevent starting, it would be BETTER to simply pull F38 (no power to heaters), and leave the O2 Sensors connected.

I do NOT know of any References explaining PCB's (circuit Boards) in the DME, and do NOT know enough about electronics to interpret it IF I had it. Statistically, the DME is NOT the problem however. If there is NO communication with a Module (you have NO communication with DME, DSC, RLS or MRS) that is most often caused by:
1) Lack of Power supply (to include Ground);
2) Lack of proper CAN bus connection (PT-CAN for DME & DSC), rather than
3) Internal Fault in Module.

FIRST Goal: is to get communication with DME Module, by testing power supply and then PT-CAN wiring.

Suggested Next Steps:
I will attach ISTA ScreenPrints to NEXT Post, which will explain the following:
1) View, Save, Attach ScreenPrints of "Fault Memory" showing fault codes in ALL Modules, but particularly in CAS & EGS Modules. Those fault codes will provide clues regarding WHY there is NO DME communication.

2) Inspect fuses F4 & F37, located on JB Fuse Panel, and test each electrically for continuity between Spades. Test sockets of each fuse for Battery Voltage. There should be be voltage at ONE (probably Left) socket of F4 with fuse removed. That socket should have battery voltage (UN-switched). F37 SHOULD have voltage ONLY with Ignition ON & F4 functioning, as it is switched by K6300, the DME Main Relay. Note & Report your findings as to each F4 & F37.

3) The idea is to get the DME communicating WITHOUT opening the E-box (where it is located). There ARE some tests that COULD be done in the E-box, but we will pass those for now.

4) Attached screenprints show location of K6300 relay at upper-right of JB Fuse Panel, SOLDERED to circuit board (next to IO1068 KL30G Relay which IS removable). Also shown is Location & Connector View of X11010. Pin #1 of that connector carries the Ground signal from DME to K6300 Electromagnet, to Activate K6300 when Ignition ON. If K6300 is functioning correctly (and it almost NEVER Fails), when Ground is applied to the Red/Gray wire (X11010/1), K6300 should make audible "CLICK".

Since I don't know your experience level with wiring diagrams or electrical testing, I'll just go that far for NOW. I would suggest taking time to understand the schematics, ask questions, either about wiring or testing, and build your knowledge base. Try to get through 1) & 2) above, and don't be afraid to ask questions.
George

[gbalthrop]

Attached are ISTA ScreenPrints related to prior post, for 2009 328i.
George

[Yoyofatboy]

Fuse 4 has good voltage out of the left socket, continuity is good through the fuse.

Fuse 37 has voltage of 12.5 with Ignition OFF, and 11.9 with Ignition ON. What im assuming this means is theres a grounding issue thats telling K6300 to always be on? This could also help explain why the fuel pump is priming with ignition on without stopping at any point. But, this shouldn't stop the communication since its stuck in ON, correct?

Attaching Fault codes as imagines inline.

Side note, the o2 sensors were disconnected at the connector near the fuel rail, but not my main concern at the moment. From what I have read, Fuse38 also controls the ECM, so as a part of my early troubleshooting, I tried to keep it from shorting out.