700h speed sensors

[rmllarue91]

Hey hef 700h 907570 right track very slow erratic. No rpm in controller for right motor. Swapped senors. Motor rpm displays on right track now not left. changed speed sensor ( no signal out put voltage ). adjusted throttle linkages did first part of calibration it passed. Shut machine off ran it around tracking to right but runs good enough figure it calibration time. When I look at controller f372 f383 both speed sensors output voltage in 2.5 ish volts...... Used one was switching low to reference voltage fine before. Re adjusted air gap no change on both. On sensor wire black is steady ground red is 5 volt reference and green seems to be 4.5 volts in ? And white is only showing 2.5 ish volts. on controller both rpms for motors seem accurate. Any ideas welcome

 

[mg2361]

Your codes indicate an electrical issue. Did you clear the codes? Perform the complete calibration? Then the codes came back?

If the fourth digit of the service code number is (0, 2, 3, or 5), an open circuit, shorted circuit, or no feed back is indicated.

F372 - This service code indicates that the Left Track Motor Speed sensor signal voltage is between 1.88 - 3.48 volts

F383 - This service code indicates that the Right Motor PCP is commanding rotation, but the Right Motor Speed Sensor is not sensing rotation and the Left Motor Speed Sensor is sensing more than 690 RPM

 

[rmllarue91]

My bad f382 and f372 both sensors feed back signal out of range. What causes these to read 1.8-3.5 volts instead of the isolating 1 to 4 volts both read rpm on trans controller. is there two circuits to these sensors?

 

[rmllarue91]

Okay answered some of my own questions 4 wire digital Hall effect sensor. Should be a dual one sensing speed one direction. I need to go back and double. Check the five volt reference and ground loaded then check both hall effects in each sensor. Then check wires to controller. Both codes come on at same time so most likely common to both sensors.