Cub Cadet RZT-S Zero Electric - Manual (Page 82)

RZT-S Zero
78
Throttle Position Sensor (TPS) faults
The TPS assembly consists of two rotary hall effect
sensors that are from the same series as the steering sen-
sor. The TPS bracket has an arm that holds a magnet. As
the arm moves, it rotates the magnet which is sandwiched
between the two sensors. See Figure 5.40.
5 volts leaves pin 8 of the VCM’s 16 pin connector.
The wire carrying the 5 volts splits and carries 5 volts to
pin 1 of all the sensor connectors on the mower. The 5
volts leaves the TPS sensors though pin 2 of their connec-
tors and returns to the VCM at pins 15 and 16 of the
VCM’s 16 pin connector. And just like the steering sensor,
the hall effect senors vary the output voltage based on the
angle of the magnet’s north pole.
The two sensors will never have matching outputs
because they are mounted on the TPS bracket facing
each other. As the magnet rotates, one sensor will
increase in value while the other decreases. It should be
noted that even if the two sensors where facing the same
direction they would most likely not match because of variances from one sensor to the next. This is why all of the
rotary hall effect sensors must be calibrated.
When the VCM calibrates the TPS, it notes the forward pedals maximum position, the reverse peddles maximum
position and the neutral position. When the drive pedal moves, the VCM monitors the TPS signals. Both signals
should change proportionally. If they do not or if one signal changes while the other does not, the VCM will display a
“Stopped: Steering sensor fault” message.
There are two failure modes of the TPS:
• A fault that generates a message
• Mechanical failure
NOTE: The TPS can have a mechanical failure that does not generate a fault message.
To troubleshoot the TPS:
1. Turn the ignition key to the “OFF” position.
2. Depress the mow in reverse and headlight buttons
with one hand while turning the ignition key to the
“ON” position with the other. This will bring up the
steering calibration screen.
3. Press the mow in reverse button.
Figure 5.40
TPS
Magnet
TPS lever
Figure 5.41
Sensor A
Sensor B