Fault 81: 48V Key Switch Undervolt-M/G - Toro Reelmaster 5010-H Diagnostic Manual

Fault 81: 48V Key Switch Undervolt—M/G
Important:
For this fault, the term "key switch" refers to the 48 Vdc logic power circuit, not to the
ignition switch.
InfoCenter Display:
Fault Description
A key switch under voltage fault is reported when the motor/generator controller measures that the 48 Vdc
logic voltage is less than 36 Vdc.
Circuit Description
The motor/generator controller monitors the 48 Vdc logic voltage.
Conditions for Setting the Fault
The motor/generator controller detects that the 48 Vdc logic voltage is below the minimum of 36 Vdc, and has
disabled the motor/generator.
Note:
This fault can occur because of a key switch issue. Therefore, if this fault condition coincides with
starting the machine, inspect the key switch.
Recommended Service Actions
Step 1: Verify that the fault repeats.
1. Clear the system faults from the InfoCenter. Refer to
2. Operate the machine.
Pass The fault did not repeat. Go to
Note:
If the fault does not repeat, an isolated event has occurred.
Fail
The fault repeated. Go to Step 2.
Step 2: Determine the troubleshooting strategy.
If only the motor/generator is reporting a key switch undervolt fault, the problem is more likely to be with the
48 Vdc logic power connection to the motor/generator. Go to Step 3.
If the motor/generator and 1 or more cutting reel motors are reporting a key switch undervolt fault, the problem
is more likely to be with the 48 Vdc system voltage. Perform the Recommended Service Actions for fault 31.
Step 3: Test the power and ground wiring in main harness connector
P37.
Use a multimeter to test the resistance between the following pairs of locations:
_____FAULT #81_____
V
48V LO
Clearing Faults from the InfoCenter (page 21)
Returning the Machine to Service (page 22)
308
.
and follow the steps listed.