Diagnostic Port Power

[1990m3]

I have been reading the archives but I can't find a definitive answer to my question.

'95 M3 OBDI Harness...

Which wire terminal needs power on the diagnostic port for a code reader to work properly? Pin 14 (big red wire) has power on my connector but I believe i read that Pin 16 (Green/White wire) should have power with the key in the "ON" position. Any advice or tips? I took my harness apart tonight so I could fix the problem, pretty sure it's Pin 16 but looking for some more knowledgeable confirmation.

Thanks

[1990m3]

nobody knows which wire needs power for the coder reader to work?

[equate975]

If it doesn't have power you probably have a problem. Did you hook everything up right???

I have the schematics let me dig them up.

[1990m3]

Pin 14 has power, but the code reader didn't work the one time I tried it. I don't have a wiring diagram

[jlevie]

Look at:

http://wedophones.com/BMWManualsLead.htm

for wiring diagrams

[bimerok]

Not to steal the thread, but I have the same problem. I connected everything and everything seems to be working, except my diagnostic connector does not work as either. I don't know if there is something else that needs to be connected at C101/x20 connection???

If anyone has any info on this please reply. Its s50 to 91 325i

Thanks.

[1990m3]

I still have the problem, bump

[bimerok]

Any one?

Any Ideas why diagnostic port has no power?

[1990m3]

fixed it after testing my friends '95 m3 (I have the same harness)

With the key in the "ON" position Pins 1, 14, 16 should all have power. Once I confirmed that these pins had power on my harness the code reader works. Finally reset my inspection light (after 2 years).

Unfortunately my car is not sending any fault codes, and it still runs like shit. So much for it pointing me in the right direction.

[Jason89i]

dave - sorry i havent responded until now. just really busy.

With the key in the "ON" position Pins 1, 14, 16 should all have power. .

oops, typo.....should be pins 11, 14, 16.

Look at:

http://wedophones.com/BMWManualsLead.htm

for wiring diagrams

strait off the etm.....chapter 0670.5

diagnostic port pins for ..... lets say a 94 325i. m3's are a little different with getting power (start imobilizer and egs, but you get the idea.)

DIAG PIN1 blk - TACH engine speed signal from dme to x20p20 to cluster.
DIAG PIN7 wht/grn- S.I. RESET signal to x20p19 to cluster
DIAG PIN11 blk/grn - PWR from ign sw in "run / start" from x20p18 (k7/k5) unloader relays.
DIAG PIN12 blu - CHARGE indicator from alt. to x20p25
DIAG PIN14 red - PWR. hot from battery junction
DIAG PIN15 wht/yel - RXD datalink from dme. also to x20p16
DIAG PIN16 - PWR in run / start from fuse box.
DIAG PIN18 - PROGRAM SELECT from dme
DIAG PIN19 - GROUND
DIAG PIN20 wht/vio - TXD datalink from dme. also to x20p17

cheers, jason

[bimerok]

fixed it after testing my friends '95 m3 (I have the same harness)

With the key in the "ON" position Pins 1, 14, 16 should all have power. Once I confirmed that these pins had power on my harness the code reader works. Finally reset my inspection light (after 2 years).

Unfortunately my car is not sending any fault codes, and it still runs like shit. So much for it pointing me in the right direction.

Did you run "jumpers" to the wires corresponding to the above mentioned pins or you fixed something at c101/x20 connection?

I was under the impression that when you connect pin 17 on x20 it should power up Diag. Plug...??? I didn't find any other pins on x20 that would power diagnostic connector.

[1990m3]

I ran a jumper to Pin 16 from the harness. Pin 14 always had power on my plug so that wasn't an issue and I didn't hook up Pin 1 (11 according to Jason).

[Jason89i]

I...........and I didn't hook up Pin 1 (11 according to Jason).

phew..... dont know what would happen to the dme /tach if it was energized w/ 12v. pin 1 (black wire) is the engine speed signal from the dme. cheers, jason

[bimerok]

I ran a jumper to Pin 16 from the harness. Pin 14 always had power on my plug so that wasn't an issue and I didn't hook up Pin 1 (11 according to Jason).

So are you planing on puting another jumper to pin 11?

Also, I just found this pinout for diagnostic port and according to it pins which should have power are: 12, 14, and 16.

[1990m3]

according to the diagram you posted, which matches my harness, it was definitely Pin 1 that had power with the key switched on.

Pin 11 is empty on my harness. I am not planning on adding a jumper pin to Pin 11, my code reader seems to be working just fine now that 16 has power too