We tried to test for continuity between CAN Hi and Lo wires from Trans module to ECU module.

Open circuit in both Hi and Lo wires. I’m pretty sure we were testing correct pins. But not positive.

Maybe there is a double break in the trans CAN bus stub?????

 

But, it seemed like the trans module picked up the 120 Ohm resistor in the Speedo.

So how could there be a break in that stub? Then it wouldn’t pick up any resistance.

 

Based on the wiring diagrams, it doesn't seem possible to see 120 Ohms looking into both the DME harness connector and the trans module connector without having continuity between the two.

Also, check your PMs.

 

Exactly, European parking lights.

 

Right, seems impossible. Might not be doing it right.

We parked the car for the night. I drove it without the transmission module connected and it acted the same way. No shifting, jerky from reverse to drive etc. but EP wasn’t shown anymore where it usually shows the selected gear. That was interesting but I’m sure it will return once module is reconnected.

Tried to read and clear codes with trans module disconnected but didn’t help. Had extra codes also obviously.

 

I checked my BMW resistance on Pins 6 to 14 of OBD port with my breakout box and it showed 60 Ohms.

 

I totally misread that page of the Bentley for the OBDII connector, didn’t I? Edit: or maybe I didn’t misread it?

If you’re getting 60 ohms, that’s good, right? Then doesn’t that also mean that the resistors in the DME and the IKE are fine? Of course, that would also have to mean that the tach isn’t connected to the CAN bus in the same manner as the other modules though. Unless I’m missing something.

 

Not sure what that is then. With Euro cars activating the turn signals with the car off should turn on the parking lights for the street side of the car. I think turning the key to position 2 would make them blink like a regular turn signal.

In your case, turning the key to position 2 without touching the turn signal stalk made the lights turn off, or they went off after returning the key back to 0?

Might not matter now, or it might be another symptom of the issue. Electrical issues are so complicated, not sure if knowing what was going on with the right side parking lights will help or add more confusion. .

 

Sorry, I checked pins 6 and 14 on my BMW M3 to see what would come up and got 60 Ohms.

Still open circuit on the MINI. The pic you posted seems to show pins 6 and 14 are unused. My daughter put in a huge effort to unscrew the plate the OBD port is mounted to, but couldn't quite get the second torx screw out. I want to see the other side of the OBD connector with my eyes to see if CAN Hi and Low wires are on 6 and 14. If not, then I don't have to worry about it, but I'm pretty sure they are supposed to be there.

 

Ah. Gotcha.

I don’t think I posted a pic of the OBD pinout; I just mentioned the page in the Bentley. I’m pretty sure you’re right that 6 and 14 should be the two CAN bus wires. What I read (misread, really) was I think a test procedure that didn’t use those two pins, which makes sense now because OBDII ports should all be mostly standardized pinouts.

 

Yes, I saw the Bentley page that didn't mention CAN bus wires on pins 6 and 14 of the OBD port. If I can get to the backside of that connector, I can solve that mystery.

 

However, it doesn’t appear in these two pics that the Diagnostic Connector port utilizes CAN bus.

But having CAN Hi and Low wires on pins 6 and 14 could be optional on some makes/models for troubleshooting maybe?

 

Huh. Maybe pins 6 and 14 aren’t CAN bus after all. It looks like maybe it wasn’t required until 2008?

 

If CAN wires aren’t in the OBD connector then that will be good news. One less thing to have to troubleshoot.

 

I think you actually posted the wiring diagram for the OBDII connector earlier here

Maybe someone with more knowledge will confirm it tomorrow, but is this why the cables for INPA have to be K-line? I think? I may have that backwards. Or is it D-CAN for the diagnostic bus?

 

Jumping in to this late. Can you check if carpet is wet on drivers side footwell? Although you checked on passenger side on BCM there is a wiring
harness that runs across the dash and picks up connectors (IKE, combi, HVAC) and goes to the X15 connector underneath the fuseblock on
drivers side. This black connectors sits on the floor and when it gets wet it corrodes as described previously in this thread (greenish discoloration =
corroded copper wires). This connector has the CAN bus wires from the IKE in it. It also has diagnostic wires for the OBDII port etc ...
I just went thru this on one of my project cars where OBD port wasnt getting power. Had to replace 3 wires. Also had problem with
rear brake light staying on all the time and problem was in that connector. And for future searches the connector number on round connector
in engine bay is X6011. On the X15 connector I have CAN L (yellow/brown) on pin 13 and CAN H (yellow/black) on pin 30

 

So I have not read your entire thread, just skimmed it & most of it is over my head anyway.
Last year I had some K-bus errors that I could not track down. Ended up being a wiring harness for an iPod on the stereo.
Figured I would throw it out there.


You can read all the details starting at Post 325
https://www.northamericanmotoring.co...ml#post4618045

 

I’m going to pull the driver’s side panel off today and check for water damage on the stuff you mentioned. Thx!

 

We added a device that controls the Kenwood stereo with the steering wheel buttons. Might need to check that.

Also have an Ian Cull device that does window operations and have garage door opener wired to it controlled by holding down door lock switch. Might need to check into that.

 

I connected my oscilloscope to CAN Hi and CAN Lo on the tach connector.

Not sure exactly how to setup scope but here’s what we found.

CAN Hi looks correct.

CAN Lo looks like it’s going both high and low from 2.5V which would be wrong.

Another mystery. Going to check driver’s footwell for water intrusion now.

 

Checked for water damage inside driver footwell near fuse box. Looks bone dry. No corrosion that we can fine.

 

Checked CAN bus resistance on that footwell connector. 120 Ohms (which is obviously wrong).

 

Based on the waveforms in the TIS bus system docs, I agree that your CAN lo signal doesn't look right. I wonder about the fall time on your CAN hi signal, too. Have you tried hooking up a second channel on the scope to see if they switch together?

 

I only have one probe but can probably get another tomorrow to test both signals simultaneously.

 

Finally got a pic of the top side of the OBD port connector. No CAN bus wires in it. Uses 7 of the available 16 pins.