New Holland T8010 Manual page 1641

Communication Lost With The Data Bus
Cause:
The armrest controller has found that it can not communicate with the Data Bus.
Possible failure mode:
1. Data Bus is not powered.
2. Data Bus is shorted.
3. Passive terminator failed.
Solution:
Make sure the armrest controller is well connected to the Data Bus.
Check the Data Bus function.
1. Check the connection to the armrest controller:
a) Make sure connector C137 is firmly plugged in to the armrest controller.
b) Make sure the armrest controller has a good connection to the Data Bus.
2. Check the power supply to the Tractor Data Bus.
A. Check fuse #42.
B. Turn the tractor key switch to the ON position. Verify approximately 12 volts power at fuse #42. If no power,
check the power supply to the key switch power stud.
3. Check the Tractor Data Bus at the can bus resistor terminators.
The following checks are performed looking into one end of the data bus and checking the resistor terminator
at the other end.
A. Check from the can bus resistor terminator at the engine. Raise the tractor hood. The resistor terminator is
located in harness that leads into Buss box. Disconnect the terminator plug at connector C205. With the
key switch in the ON position, measure the voltage on each pin to ground on connector C205.
At cavity A, the yellow wire, it should read from 2.5 to 2.8 volts.
At cavity B, the green wire, it should read from 2.2 to 2.5 volts.
If the above checks are ok and all controllers came online, it means that the opposite end resistor
terminator and the data bus wiring are functioning correctly. The engine end resistor terminator has most
likely failed. Test the engine end resistor terminator and replace if it has failed. See step 4.
B. Check from the can bus resistor terminator in the TMF controller.
Reconnect the engine end resistor terminator and disconnect the TMF controller connector C053.
With the key switch to OFF, then to ON. Measure the voltage between the following cavities at connector
C053.
At cavity 15, the yellow wire, it should read from 2.5 to 2.8 volts.
At cavity 16, the green wire, it should read from 2.2 to 2.5 volts.
If the above checks are ok and all controllers came online, it means that the engine end resistor
terminator and the data bus wiring are functioning correctly. The TMF controller resistor terminator has
most likely failed. Test the TMF resistor terminator and replace if it has failed.
4. Use a multimeter to check the resistance on both can bus resistor terminators. The resistance at TMF
controller connector C053 from pin 15 to 16 should be 120 ohms. The resistance at the engine end resistor
terminator plug pin 1 to 2 should also be 120 ohms.
5. Split the Data Bus by disconnecting connector C333. Turn the key switch to OFF, then to ON.
A. If none of the controllers come back on line, the problem is inside the cab. Check the Data bus wiring in
the cab for open circuits or shorts to ground. If the problem cannot be found in the wiring, disconnect each
controller one at a time to determine if one of the controllers has failed.
Section 55 - Electrical System, Controller - Chapter 5
FAULT CODE ARM 12013
55-5-36