OBD2 port pin 16 gives 6,7 volt only. Cannot get the scanner to work

[Zahar8088]

Hello everybody, I'm new to this, so I'll try to be short and to the point:
My 2001 bmw 740i obd2 port pin 16 gives only 6.7 volt when the key is off.
With key in and in position 1 it gives 8 volt
With key in position 2 it grows to 8.2 volt
Please, any advice will be appreciated
Thank you

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With the car running, voltage grows from 8v to 9.2 volt in about 7 seconds

The sunroof used to leak during rain (fixed now) and I had water in glove box once.
Fuse 51 (vent/sliding roof) has a little shorting, about .5 amp

[Mayorchuck]

Towed to E38 forum

[psjr]

I would check under the passenger carpet for water damage to electronics.

[Mayorchuck]

Welcome to the forum. The OBD II Pin 16 gets it's power from Fuse 27. Fuse 27 is within a group of fuses that comes from Fuse 110. That fuse, and wire splices, are under the passenger seat. That fuse block is in the lowest point of the floor pan under that seat. It is OFTEN where the water from the sunroof drains finds it's home.

[Zahar8088]

Wow, thanks a lot guys!
I appreciate your advice. On my way to rip off the carpet..lol

[Zahar8088]

Ok, so i got to the fuse box under the seat, there was some water. I checked all fuses - all good. Couple contacts been corroded. I dried all water, cleaned up the contacts, now i have 7,5 volt from pin16 when car is off and 9,8 volt when it runs.
Any suggestion for a next step??
I cann't get my obd2 scanner to work;-(

[psjr]

Did you check the splices in the wiring harness holder trim?

[Zahar8088]

Would you be able to send a picture please?
there are quite a lot of wiring ..

[psjr]

http://www.bimmerforums.com/forum/showthread.php?2027345-The-MID-wasn-t-working-Fuse-Block-under-pass-seat

[chris33]

Be sure the under hood OBD cap is on securely.

[mboor]

Be sure the under hood OBD cap is on securely.

+1. fWIW, i've had issues on an off with OBD2 port communication also. i have no clue why, but when the obd2 cap is left off INSIDE the car it can cause the same issues as the under hoop cap (at least on my car) I Spend days trying to figure out why i could communicate via obd2 port. The cap had been left off for quite a while. I secured the cap back into the obd2 port, turned the ignition off for 5 mins and gave it another try. All of a sudden my cheap scanner was able to talk to my 750il through the obd2 port. I done this several times, with the same result, so i know im not crazy.

On the interior OBD2 port cover there is 2 pins which are inserted into the plug when its secured. I have to assume they have a similar function as the grounding pins in the round 20 pin underhood port.

[Zahar8088]

Hey PSJR, thanks for the link, but unfortunately the pictures don't load up.
my guess is that you mean these splices: http://i.imgur.com/yai5N9ph.jpg
am i right?

And the cap under the hood is on securely, thanks chris33;
mboor, im just curies if your obd2 scanner didn't power up when plugged in or it didn't communicate with a car?

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Why I can't post or watch pictures in this forum???????

[Mayorchuck]

New members are restricted from posting pics or links, without approval, as a spam preventative. Once you get your post count up just a little, this restriction will go away. For now, if you use a host site like Photobucket, you can paste the IMG link into the post. It will put it to moderated status for one of us to approve. To post pics using the forum, you have to reduce the photo quite a bit.

[Zahar8088]

That's understandable. Thank you for quick response. Mayorchuck, can you tell how long until the restriction goes away and also why I can't see the pictures from the link psjr had sent earlier?
are the pictures deleted already?

Sorry, I'm just really trying to figure out the issue with my car

[Mayorchuck]

I believe it's 15 posts but it seems to vary and is often less. I don't see Paul's pics either. He probably used a host site and either moved or deleted the pics. I believe this is one of his pics I had saved. A few of the splices he is referring to are on the right here.

http://i845.photobucket.com/albums/ab16/Mayorchuck/E38/passseatfuses.jpg (http://s845.photobucket.com/user/Mayorchuck/media/E38/passseatfuses.jpg.html)

[Zahar8088]

Got it! Thank you Mayorchuck,
My wires ware not as bad....) so the splices on the right are ground, right?
because in my obd2 port pins 4 and 5 have good ground, only my pin 16 seems to be lagging:(

[Zahar8088]

Hey guys,
Now my pin 16 has no power at all.. All the positive cables under the front pas seat have 12 V, the fuse 27 under the hood has 12 V
Any suggestion where to look next?
Could it be my ECU??
The car is running fine

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On bmw planet from the obdII wiring diagram i see that pin 16 is connected directly to fuse 27
my question is where can I lose 12 V??
If i put the meter to the fuse 27 and the pin 16 in the port, I should get the continuity, am I right?

[Mayorchuck]

Sorry to be Capt. Obvious but are you getting 12v on both sides of Fuse 27? If so, yes, you should have continuity.

[Zahar8088]

I thought that only one pin under fuse 27 suppose to give voltage and the fuse, like a bridge, transfers the voltage to a second pin which should have continuity with pin 16 in obd2, correct me if Im wrong

So my answer is no, I do not have 12 v on both sides of fuse 27, also I've just checked - i do not have continuity from neither pin on fuse 27 to pin 16 in obd2 port
my guess i have a broken wire, or is there any other element on the way from fuse 27 to obd2 port??

[psjr]

Sorry about the issues with the pictures, it turns out that image hosting site has blocked bimmerforums.
You didn't mention if you have checked the splices I was talking about, which is the only place that fuse 27 could have an issue between the fuse and the OBD port.

Under the passenger seat, forward of the white fuse box, is a black box integral to the wiring harness holder trim.
You need to unfasten the black plastic wiring harness holder trim from the car so that you can flip it over and look at the splices in there.

[Mayorchuck]

This is the only other shot I have of the area if that helps.

http://i845.photobucket.com/albums/ab16/Mayorchuck/E38/a1463db7-9e7e-467b-9a7e-cd02d7eea2c5.jpg (http://s845.photobucket.com/user/Mayorchuck/media/E38/a1463db7-9e7e-467b-9a7e-cd02d7eea2c5.jpg.html)

[Zahar8088]

Thank you for your help guys! Psjr you ware absolutely right. Under the black box my wire was corroded and it broke.
It's the same wire that goes to pin 16 (red with yellow).
Appreciate the advices .
Now my scanner works but gives: 'fault in communication with vehicle ecu' when I'm trying to scan
I disconnected the battery when I was cleaning/replacing the contacts
Any suggestions?

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What could be the reason for : 'fault in communication with vehicle ecu'?

[740iSport303]

Make sure cover is fully installed on the under hood 20 pin connector.

[Zahar8088]

So found some info about scanning codes from inside OBDII port: apparently, you can read ONLY powertrain data from inside obd2 port, and if you need to get codes from ABS/SRS etc. you have to go to the Data link connector under the hood
Is that right information??
I can provide link to the forum (not sure if I can post it here, but i'll try: http://forum.e46fanatics.com/showthread.php?p=15898864

and thanks for the tip 740iSport303, the cap is secure under the hood (http://www.bimmerforums.com/forum/member.php?273621-740iSport303)

[psjr]

So found some info about scanning codes from inside OBDII port: apparently, you can read ONLY powertrain data from inside obd2 port, and if you need to get codes from ABS/SRS etc. you have to go to the Data link connector under the hood
Is that right information??
I can provide link to the forum (not sure if I can post it here, but i'll try: http://forum.e46fanatics.com/showthread.php?p=15898864

and thanks for the tip 740iSport303, the cap is secure under the hood (http://www.bimmerforums.com/forum/member.php?273621-740iSport303)

Yes, that is correct.

You can modify the cap under the hood to get all the data at the OBD port, or you can buy a $6 OBD-20 pin adapter.

http://www.amazon.com/Pin-OBD-Scanner-Adapter-Cable/dp/B00V81X18S/
http://www.bimmerforums.com/forum/showthread.php?1903575-OBD-Port-Mod&p=25716631#post25716631

[Zahar8088]

Got it!
Thanks a lot PSJR and Mayorchuck.