Speed sensor, no clue whats going on.

[equate975]

Ok, I have the e34 wiring harness which as been a PITA since day one. I am also using the sliver 413 ECU.

Heres the deal, I keep getting a speed sensor code. My speedo works, which makes me think its the connection between the speedo and the ECU.

Looking at the ETK, according to the 91 e34 with the m50, the ECU wiring harness gets the speed signal sent to pins 67 and 68.

If I look at the e36 ETK, it says pins 67 and 68 are not used, and I cannot find ANYTHING about a speed input anywhere on the ECU diagrams. The only thing I see is in the wire chart that says "Vehicle Speed Sensor" on pin 42, but its only listing the one wire, that says its an input from the cluster.


WTF?

[325Projectz]

What year is your car?

I had to connect my last m50 swap through the glove box to fix the speed sensor. There is a 3 wire/pin harness in there. Its one of those wires, I have a pic but I need to dig it up.

[equate975]

Its an 88 m3 I used that harness you are talking about to hook my tach up.

I found pin 7 on the blue wiring harness on the cluster is supposed to send the signal to the ECU. I used a tone tester and I think its getting sent to pin 46 on the ecu. However, the ETK says for a m50 325i that it should get sent to pin 42 on the ECU. But, the e34 525i with m50 gets a signal directly from the diff on pins 67 and 68.

EDIT:

THR said in the middle of 88 they changed some way that somthing was wired, thats why I needed to tap into that 3 wire plug.

EDIT again:

I see pin 44 is a ground, I bet that stupid tone tester is just hopping the grounds on me again. These things really dont work in cars..

[Ryan Stewart]

I had to use one of the extra outputs ffrom the cluster (the green clipped on socket) that is for the cruise control and run a wire over to the plug by the DME and hook it up. If its not hooked up you will be hitting a shorter revlimiter.

[EtaSport]

If its not hooked up you will be hitting a shorter revlimiter.

I have been looking for this answer for months. I've had the "fault code" ever since the motronic swap. I dont have a cel, but everytime I plug the reader in its there. Ive never hit the revlimiter because I hate spinning my cranky eta much over 6k for long, but I did want to know how to rid it.

[equate975]

I had to use one of the extra outputs ffrom the cluster (the green clipped on socket) that is for the cruise control and run a wire over to the plug by the DME and hook it up. If its not hooked up you will be hitting a shorter revlimiter.

I hear at WOT vanos needs the speed reading or it wont run correctly?

Do you remember what wire on the DME you hooked up to? Im pretty sure its 42 I just want to make sure before I start cutting it up again.

Thanks for the help guys

[BimmerToad]

the vehicle speed input originates from the speedometer gauge in the cluster.

[equate975]

Problem solved.

If anyone is wondering, I took a green wire on this 3 pin harness that has a speed signal from the cluster. I hooked it into pin 42 on the DME, no mocde code :)

Thanks for the help BimmerToad and 325Projectz

[Ryan Stewart]

No fucking love, eh? :(

[equate975]

haha and thanks Ryan Stewart :-P

[Ryan Stewart]

ahhhh, recognition! :)

FWIW, I recall the wire being black/white. I could be wrong but if I am then its white/black.

[NickP]

ahhhh, recognition! :)

FWIW, I recall the wire being black/white. I could be wrong but if I am then its white/black.

Yeah it was white/black or black/white on mine as well - there's different colours depending on the year.

I forget if its the OBC or cruise control - but if you don't have one - you'll have to run the wire from the green wire on the cluster.

[equate975]

Did you guys have to run anything to the OBC? Mine is dead, just says im gettin 5.9 MPG, however it can determine the average MPH just not my fuel consumption or range.

[EtaSport]

On mine I had to run the fuel consumption rate pin to the c104 connector. Im sure its different on yours. Thats the wire you want though.

[equate975]

Is that on the cluster too? Which one was the c104 again?