Throttle Module; Throttle Module (Using Test Harness) - Taylor-Dunn B0-248-TT Operation, T Roubleshooting And Replacement Parts Manual

Maintenance, Service, and Repair

Throttle Module (using test harness):

The throttle module is located under the floorboard and functions as a throttle position sensor. The
throttle module has two output signals, one is a varying voltage relative to the pedal position and the
other is a fixed voltage indicating that the pedal is depressed.
Other than the FS-1 switch, there are no static tests for the module. To test the module, it must be
connected to a power source. To bench test the FS-1 switch, check continuity between pins #4 and
#5. Should be closed only when the pedal is depressed. If open, replace the module.
The module can be bench tested by applying 36 volts to module pins #7 (+) and #9 (-).
For this procedure, the module will be tested while in the vehicle using the 75-089-00 test harness.
Testing in the vehicle will also help in identifying certain vehicle wiring faults.
The test harness plugs into the throttle module and vehicle harness. It has a long extension with a
connector that allows for direct voltage tests to all of the wires going to and from the module. The
vehicle should not be able run while the test harness is connected.
This illustration shows the test end of the harness and the orientation
of the terminals. The terminal numbers shown are exactly as on the
test harness.
NOTE: Perform the test for Pin #9 first, then use pin #9 as the battery
negative reference for all other tests.
Pin #9, Pegative Power Supply Input:
> Referencing battery positive, should be full battery voltage.
If not correct, check wiring.
Pin #7, Positive Power Supply Input:
> 48 volt system: Should be Battery Volts.
> 72 volt system: Should be between 25 and 40 Volts with the key switch ON (ISO
contactor closed).
If out of range, check dropping resistor (72v system only) and wiring.
NOTE: 72 volt system, an incorrect voltage could also be a result of a faulty module.
Pin #1, #3 , #6, #8 - Not used on this vehicle.
Pin #2, Throttle Position Output:
> Test voltage while slowly depressing the throttle pedal. The voltage should vary
between 6 Volts (creep) and 11 Volts (full speed).
If out of range AND Pin #7 AND Pin #9 tested good, then replace the module.
Pin #4, FS-1 Input:
> Should be Control Volts (nominal).
If not correct, check wiring and switches.
Pin #5. FS-1 Output:
> With pedal UP, should be 0 Volts. With pedal depressed (any position) should be
Control Volts (nominal).
If Control Volts with pedal up, then check module FS-1 for welded contacts or vehicle
wiring for shorts. If FS-1 welded, replace the module.
If not Control Volts with the pedal depressed AND Pin #4 tested good, then replace the
module.
Electrical Troubleshooting
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