ok, ive gotten a LOT of emails pm's like this in the last week .
let me try to clearify. Ususally i get on my soap box and preach 'learn how to read and etm" and "you MUST make your own wiring chart" ... BUT.... i see this issue popping up a lot..... So, here's what i know.
DO I NEED A SPEED SIGNAL?
unless you have a custom chip that deletes the speed signal, you NEED the speed signal hooked up to the dme . If it is not hooked up, your ignition, fueling, load map, rev liimit and vanos will be effected.....IN A BAD WAY. if the dme does not think your car is moving, and it will limit / detune the motor.
IS MY SPEED SIGNAL HOOKED UP?
check with a scanning tool, like a gt-1. or use the peake tool to read the stored codes in the dme. it will display "speed signal" error codes. ...... oh wait. I forgot. this is R3V....... put your car on a hill, clutch in, engine idling, not moving. should be 7-800 rpms. now, without touching the gas pedal, (engine still running, clutch still in) remove the brake and allow the car to roll forward. as the speedo begins to register, you should notice the rpm's raise to 900-1000. VIOLA.
SO WHERE IS THE SIGNAL?
on later 87+ (verify with YOUR CARS wiring diagrams) it comes from the cluster to the cruise control, to the obc and to the dme..... via the c101 p14. its a BLK/WHT (standard e30's) or a BLU/YEL wire (some e30 m3's). (BLK/WHT = BLACK wire / WHITE stripe. )
on earlier 87- (verify with YOUR CARS wiring diagrams) it comes from the cluster and goes to the obc and cruise control unit.
plugs on back of cluster
c1 = blue 26 pin connector
c2 = white 26 pin connector
c3 = yellow connector
for an 86 e30 (usa car.) brown wire / red stripe = br/rd
c2 p12 br/rd - speed signal input from diff to speedo
c3 p26 br/rd - speed signal output from speedo to obc
c6 bu/yl - speed signal output from speedo to cruise
obc p21 br/rd - speed signal output from speedo to obc
WHERE DOES THE SIGNAL GO?
the signal goes to the dme.
it does depend on which dme / harness you are using, but typically its at the x20p14. (verify with YOUR DME / HARNESS wiring diagrams)
e36 (m50tu, s50, s50b32) x20 p14 is a BLK/WHT wire.
e34 (m50) x20 p14 is a BRN/RD wire.
MORE TO COME.....
i guess a little search never hurt either.....
hope this helps.
cheers, jason
Leave a comment: