New Holland T8010 Manual page 1468

Ground Speed Signal Failed In The Instrumentation Controller
Cause:
The Data Bus signaled that the transmission speed sensor has failed.
The AUX/Hitch/PTO controller received the signal from the instrumentation controller.
Possible failure mode:
1. The transmission speed sensor failed (in most cases).
2. Software execution error in instrumentation controller (small chance).
WHEEL SPEED SENSOR INFORMATION
Cavity A: Signal
Cavity B: Ground
Operating Temperature: - 40 degree C to 125 degree C
Resistance: 2700 to 3300 ohms
Inductance: 1.9 to 2.9 H
Output: 30 Hz to 7 kHz Quasi-Sinusoidal
Solution:
The speed sensor is hard wired to the instrumentation controller. The instrumentation controller sends the wheel
(transmission) speed signal to the hitch controller and the PTO controller via Data Bus.
If the sensor or the instrumentation controller has a problem, both fault code AUX/Hitch/PTO 32 and AUX/Hitch/
PTO 87 should appear.
1. If the service tool is connected to the tractor, do the following:
Go to the Monitor screen by clicking on the Monitor Icon.
Click the CHANGE PARAMETER SELECTIONS Icon.
Select the INST GROUND SPEED - WHEEL and then ADD.
You will be able to monitor the wheel speed sensor signal on the screen.
Drive the tractor and watch the signal change when the tractor speed changes.
If there is no wheel speed signal, go to step 2.
If there is wheel speed signal, compare it to the speed display on the instrumentation cluster.
If the speed signal looks fine on service tool but not on the instrumentation cluster, it is more likely a problem
with the instrumentation cluster.
If both signals seem fine, check the function of the AUX/Hitch/PTO controller.
2. Test the resistance of the transmission speed sensor:
Locate the transmission speed sensor on top of the transmission.
Disconnect connector C069 from the sensor.
Inspect the connector. Clean the connection.
Measure the sensor resistance between pin A and Pin B.
The resistance should be around 3 k ohms at 20 degree celsius.
If the resistance is not in the specified range, replace the transmission speed sensor.
If it is as specified, go to next step.
3. Check the wiring from the transmission speed sensor to connector C060 and then to connectors CN-1 and CN-
2 at the instrumentation controller.
There should be 5 VDC power supply from pin 12 of CN-1 to pin A of connector C069 when the tractor key is in
the 'RUN' position.
There should be good continuity from pin B of connector C069 to the clean ground.
Check for open circuit and wiring shortage.
4. If none of above, check the function of the instrumentation controller and the AUX/Hitch/PTO controller.
NOTE: Always inspect connector ends for damaged, bent or dislocated pins when troubleshooting.
NOTE: See schematic sections 24, 25 and 26 on the schematic poster.
Section 55 - Electrical System, Controller - Chapter 3
AUX/HITCH/PTO FAULT CODE 87
55-3-49