speed input on v44

[max]

hello i wonder if anyone can help im trying to get the ecu to read a speed input but i cant get it to read anything.

ive setup di1 to speed and tried with pull up resistor on and off active edge both rising and falling and tried all sorts of numbers in the calibration but get no reading.

on the runtime page i get nothing di1 says off and frequency says 0.0 always.

ive eliminated it being wiring as a changed di1 to gp input then earthed it ot and it turned on in the runtime screen.

its running a autometer gps interface into a stack dash and ive tapped in to the signal wire from that witch is violet and wired that straight in to di1 of the ecu.

i dont expect it to be all that accurate paticualy at pull off and low speeds i just wanted a reading so i  can use the gears for boost control.

i did wonder if interference on the wire could cause no reading but id have thought i would get an erratic reading not nothing

[Simon]

What type of sensor is being used/ VR or HAll/Optical?

For a VR sensor you need to get the speed up enough to have the positive voltage go above 1.5V before the Di will register it. 

[max]

it says it uses a 12 volt square wave signal. so could it be im not going fast enough or im not getting enough voltage

[Adamw]

Was the stack dash showing a speed when you were testing it?  I would expect if the dash is showing a speed the ecu would.

[max]

yep stack dash reads speed  when testing. im going to play about with settings in the stack dash tell it it has more pick up points then re calibrate the gps to the the stack dash im thinking maybe its not enough to get above 1.5 volts

[max]

changed the settings still getting no reading even though the dash is reading speed what would be better increasing the number pickup points over the wheel circumferance or reducing the number I've raised them and has made no difference. could interference on the wire cause it to not read anything I doubt it but running out of ideas.

[Simon]

Try setting the Di input to Frequency, Pullup I would expect to need to be off. Edge is not likely to matter. then see if you have any frequency.

If you don't then next step would be to scope the output of the GPS to see what sort of wave form you have.

[max]

ok i will try that and report back

[max]

tried it on frequency and getting nothing still ive now ordered a abs sensor the hubs have hole and trigger for one. pretty sure there vr sensors should i use a shielded cable to wire it thanks for the help