New Holland T8010 Manual page 1622

The Hitch Upper Limit Control Failure
Cause:
Hitch upper limit potentiometer has failed.
Possible failure modes:
1. The hitch upper limit control potentiometer failed.
2. Bad connection between the armrest controller and the second panel.
3. Armrest controller failure.
Solution:
The hitch upper limit control potentiometer is mounted on the second panel and wired to the armrest controller. The
potentiometer position information is broadcast over the Data Bus and can be monitored in the monitor screen of
the service tool.
All controls on the second panel are built in as an integrated part with the second panel. If any control fails, the
whole second panel must be replaced.
All controls on the second panel share the power supply and ground. All control signals with the power supply and
ground are connected to the armrest controller through connector J2.
If the power supply or ground from the armrest controller is bad, all the controls on the second panel will show fault
codes. It means all the following fault codes will be recorded at the same time.
ARM 89, ARM 99, ARM 109, ARM 119, ARM 139, ARM 149, ARM 159, and ARM 169.
If a single fault code is recorded, it is more possible that the potentiometer or its wiring to the armrest controller has
failed.
Whether it is a single or multiple fault codes, always check the connection between the second panel and the
armrest controller first. Make sure there is no damaged wires, loose connections, or bent pins.
It is hard but possible to test the hitch upper limit control potentiometer and the wiring circuit.
1. Open the armrest controller housing and disconnect connector J2 of the second panel from the armrest
controller.
2. Check the potentiometer:
a) Measure the continuity between pin 1 and pin 2 of J2. The resistance should be approximately 2 k ohms.
b) Measure between pin 2 and pin 8 when turning the potentiometer, the resistance should change
continuously from 0.1 k to about 1.1 k ohms.
If the potentiometer or its wiring is bad, replace the second panel.
3. Check the power supply:
a) Turn tractor key switch to the ACC position.
b) Check the power supply from the armrest controller at pin 1 of J2. It should be approximately 8 volts.
If the power supply from the armrest controller is bad, replace the armrest controller.
4. If none of above, clean the connectors and reconnect the second panel to the armrest controller.
Calibrate the armrest controller and check the fault code again.
If no fault code is recorded, the problem is fixed.
If the fault code is recorded again, replace the armrest controller.
NOTE: See schematic sections 47 and 48 on schematic poster.
Section 55 - Electrical System, Controller - Chapter 5
FAULT CODE ARM 149
55-5-17