Fault Code Inst 12091 - New Holland T8010 Manual

Communication Lost With Engine Controller
Cause:
Communication lost between the instrumentation controller and the engine controller.
Possible failure modes:
1. Bad connection between the instrumentation controller and the engine controller.
2. Controller failure.
Solution:
Make sure both the engine controller and the instrumentation controller are functioning properly.
Check the Data Bus connections.
1. Check the function of the engine controller.
A. Make sure the connector to the engine controller is plugged in and the Data Bus connectors are all
properly connected.
B. If the engine controller is correctly connected with the Data Bus, then the fuel lift pump will buzz when the
key switch is turned to the ON position. If the fuel lift pump does not make noise with the key on, replace
the engine controller.
NOTE: Refer to the engine controller troubleshooting procedures.
2. Check the function of the instrument controller.
A. If there is no display and no back light on the tractor instrumentation, it is most likely that there is no power
to the controller. Check the power supply, its fuse and the ground to the controller. Make sure the
connectors CN-1 and CN-2 to the instrumentation controller are plugged in.
B. If there is a display on the tractor instrumentation but the display is erratic, such as unusual symbols, and
other controllers claim communication is lost with the instrument controller, it is most likely the instrument
controller has failed. Replace the instrument controller.
C. If the display is normal, go to number 3.
3. 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.
4. 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.
B. Check from the can bus resistor terminator in the AUX/Hitch/PTO controller.
Reconnect the engine end resistor terminator and disconnect the AUX/Hitch/PTO 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 AUX/Hitch/PTO controller resistor
terminator has most likely failed. Test the AUX/Hitch/PTO resistor terminator and replace if it has failed.
Section 55 - Electrical System, Controller - Chapter 2

FAULT CODE INST 12091

55-2-21