Found a wiring diagram on net but its quite blurry is it is a trail and signal wire goes to engine ecu but found this info on another site and according to it the GIU (gearbox interface unit there name for TCM) doesn't control the signal from sensor i am testing so it looks the the ecu deals with the sensor input.
Complaint:
Car Will Not Achieve More Than 2000rpm, Stuck in Single Ratio
Fault Code P0722 Logged
Check:
Output Speed Sensor Circuit – Use Test-book in Real Time Monitor (CVT Parameters) to See If Road Speed Signal Ok
Check for Debris Across Sensor Pick - up
Substitute MEMS ECM if Signal and Wiring Ok
Just had a look at the meassurings.
Looks to me like your sample rate is to low.
Because of this it looks like the voltage drops down when the frequense rises.
If you send me your email adres then I can send you a wiring diagram.
Last edited by arjen on Thu Mar 07, 2013 7:12 am, edited 1 time in total.
I will maybe phone them tomorrow and see what they say about a diagram, There is a road speed transducer sensor, output speed sensor, an inhibitor switch and a ratio control motor. No signs of mechanical faults took the car a 20 mile run and didn't miss a beat, stopped, 10 mins later took it a run again and it happened within a mile so i stopped and left car turned off for 5 mins then drove back to workshop and it was fine again so its a strange one!
I have looked at your so called good speed sensor again and it looks like the supply voltage to the speed sensor are missing sometimes !!!.
At first eye sight, I thought the signal was missing and indeed it does, but I´m more and more convinced that somewhere at the supply wire, that the voltage is being disturb - it could also be that sensor itself is shortcircuited.
With the help of the right wiring diagram i´m sure you will be able to pinpoint this problem correctly.
I think at the point you have mentioned i stopped the car, turned ignition of, restarted car and drove back to workshop but i can't quite remember but that would account for why the supply dropped and came back at that point. If you look at my 'bad' capture the signal stays at 14v the entire capture while the signal is dropping off and fault occurs but i'd have to redo the capture to be sure. I will redo it at some point just trying to find time among other jobs.