New Holland T8010 Manual page 1526

PTO Is Configured As A Two Speed And No Shaft Size Frequency Was
Detected When The PTO Was Switched On
Cause:
The module is receiving no frequency from the shaft size sensor when configured as a two speed PTO tractor.
Possible failure mode:
1. The PTO system is equipped with only shaft speed sensor but configures as two speed system.
2. PTO shaft size sensor is not well connected or failed.
3. Wiring problem between AUX/Hitch/PTO controller and the PTO shaft size sensor.
PTO SHAFT SPEED SIGNAL
The PTO shaft speed frequency is derived from a variable reluctance speed sensor in the transmission. The clutch
speed sensor is connected directly to the AUX/Hitch/PTO control module in all versions of the PTO control system.
The sensor output is directly proportional to PTO clutch output speed, and is a quasi-sinusoidal wave form the
amplitude of which is non-linearly proportional to speed. The amplitude range of the signal is from 3 volts peak-to-
peak to 80 volts peak-to-peak centered around chassis ground. Frequency range is from zero to 3,200 Hz worst
case.
PTO SHAFT SIZE SPEED SIGNAL
The PTO shaft size speed frequency is derived from a variable reluctance speed sensor in the transmission. The
sensor is connected directly to the AUX/Hitch/PTO control module and its output is proportional to PTO clutch
output speed, but scaled differently from the PTO clutch speed signal depending upon which PTO shaft is in use.
i.e. 1-3/4" 1000 RPM, 1-3/8" 1000 RPM or 1-3/8" 540 RPM. The signal is a quasi-sinusoidal waveform the
amplitude of which is non-linearly proportional to speed. The amplitude range of the signal is from 3 volts peak-to-
peak to 80 volts peak-to-peak centered around chassis ground. Frequency range is from zero to 760 Hz worst
case.
Solution:
Make sure the tractor has the PTO dual speed (shaft size) sensor installed and properly connected.
Check the wiring from the AUX/Hitch/PTO controller to the shaft size sensor.
Test the function of the sensor.
1. Make sure the tractor has the PTO dual speed (shaft size) sensor installed and properly connected. If not,
either reconfigure as a single speed sensor PTO system or add the shaft size sensor to the tractor.
2. Check the wiring harness to the PTO dual speed (shaft size) sensor.
Check the continuity from Pin 21 of connector C054 to Pin A of connector C336.
Check the continuity from Pin B of connector C336 to the chassis ground.
3. Check the function of the shaft size sensor. It should have resistance of about 3 K ohms.
NOTE: Always inspect connector ends for damaged, bent or dislocated pins when troubleshooting.
NOTE: See schematic sections 49 and 50 on the schematic poster.
Section 55 - Electrical System, Controller - Chapter 3
AUX/HITCH/PTO FAULT CODE 179
55-3-107