New Holland T8010 Manual page 1604

Backup alarm circuit shorted or open
Cause:
The transmission controller monitors the backup alarm circuit. If the transmission controller detected open circuit or
too much current draw in the backup alarm circuit, this fault code will be recorded.
Possible failure mode:
1. The backup alarm failed.
2. The backup alarm wiring failed open or shorted to ground.
Solution:
1. Remove the controller cover from the rear of the tractor. Visually inspect the wiring harness from the
transmission controller towards the backup alarm. Check for abnormal routing and wire damage.
2. Disconnect connector C355 from the transmission controller.
Measure the resistance between cavity 9 of connector C355 and the ground at the wiring harness side.
The resistance should be around 2 to 5 ohms.
If the resistance is dramatically higher than specified, there is an open in the circuit.
If the resistance is close to 0, there is a shortage to the ground.
Check the harness. If the harness is OK, check the backup alarm.
3. Check the backup alarm.
Disconnect the backup alarm at either connector C338 or C337.
Measure the resistance between pin 1 and pin 2 of backup alarm.
The resistance should be around 2 to 5 ohms.
If the resistance is dramatically higher than specified, the backup alarm is failed open.
If the resistance is close to 0, there is an internal shortage.
In either case, replace the backup alarm.
4. If no problem is found in above test, check both male and female pins in the cavity 9 of connector C355.
Check for no loose pin, bent pin, or any damage.
Section 55 - Electrical System, Controller - Chapter 4
FAULT CODE TRANS 148
55-4-77