VSS not seen by ecu
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Joined: Feb 2008
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VSS not seen by ecu 90 240sx, 01 corvette motor and trans, 98 harness and ecu.
Ecu is not seeing speed signal, and therefor not shifting the auto tranny into the next gear. I traced the yellow and purple wire down to the speed sensor and they are fine no problems there. Replaced the speed sensor, same problem. ECU is not seeing VSS signal. Does anyone have any ideas what could be going wrong? Are there any other wires that tie into the VSS? I have the green white stripe (vss output) going into a dakota digital and it doesnt seem to be getting signal either. Anyone have any ideas??? please help.
updated. Changed ecus, doulbe checked wiring. Tested and replaced VSS... still no signal being seen by the ecu, does anyone have any ideas?
Ecu is not seeing speed signal, and therefor not shifting the auto tranny into the next gear. I traced the yellow and purple wire down to the speed sensor and they are fine no problems there. Replaced the speed sensor, same problem. ECU is not seeing VSS signal. Does anyone have any ideas what could be going wrong? Are there any other wires that tie into the VSS? I have the green white stripe (vss output) going into a dakota digital and it doesnt seem to be getting signal either. Anyone have any ideas??? please help.
updated. Changed ecus, doulbe checked wiring. Tested and replaced VSS... still no signal being seen by the ecu, does anyone have any ideas?
Well this may sound like a dumb question but is there a reluctor ring on the output shaft?
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Not sure how to reply to this.......2001 corvette=C5. These units do not have a reluctor on the output shaft. The differential bolts directly to the trans. I believe they get the signal from the differential. If this is how the car is set up then the output shaft does not have a reluctor.
I didn't notice it was a corvette 
guess i should have read closer don't know how I didn't see that.
guess i should have read closer don't know how I didn't see that.
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sorry i should clearify a little better. Its a camaro trans, and yes the reluctor ring is in place, and it does spin with the wheels and tires moving. I read somewhere else some guy stuck strait 12v power to one of the wires on the speed sensor and it started working? someone else told me that it needs a 5v reference signal, but as far as I can tell this is a PM generator and wouldnt require and power or ground to operate? if someone could just clearify how the circuit operates, i might be able to figure this out but i cant find any information on what is supposed to be going on down there. Is it a pulsed signal? does it generate a voltage/amperage that increases/decreases with vehicle speed? I cant find anything online about it and alldata(nodata) was of no assistance.
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Joined: Oct 2006
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From: Paulden, AZ
VSS tranny Problem I just figured out why my tranny was going nuts! My tranny guy rode along with his DX box in his lap and found the PCM was reading the vehicle speed up and down like crazy. The problen was that my Autometer Spedo was wired into the VSS HIGH signal from the speed sensor on the tranny. Rewire the spedo to the VSS out from the PCM. On my 2002 harness it is C2 pin 50.
Bill
My tranny guy rode along with his DX box in his lap and found the PCM was reading the vehicle speed up and down like crazy. The problen was that my Autometer Spedo was wired into the VSS HIGH signal from the speed sensor on the tranny. Rewire the spedo to the VSS out from the PCM. On my 2002 harness it is C2 pin 50.Bill
