78
Users Manual
38
How to Use the Bar Graph to Test a
Throttle Position Sensor
The bar graph shows readings relative to the full-scale
value of the measurement range. (The range is shown at
the right of the bar graph.)
For example, if the meter is in the "4V" range, the num-
bers on the bar graph scale represent 0, 1, 2, 3, and
4 V. If the meter is in the "40V" range, these same num-
bers represent 0, 10, 20, 30, and 40 V.
Note
When measuring frequency, the meter displays
frequency on the digital display and shows the
voltage of the input signal on the bar graph. This
allows you to see if a hazardous voltage is pres-
ent.
To use the bar graph to observe the sweep on a throttle
position sensor (TPS):
1. Insert the test leads in the jacks (Figure 17).
2. Turn the rotary switch to
Ω
.
3. With KEY-OFF/ENGINE-OFF, disconnect the TPS’s
electrical connector. Then connect the test leads to
the sensor as shown.
4. Slowly open the throttle while watching the bar graph.
5. As the resistance increases, the bar graph moves
slowly if the TPS is good and moves erratically if the
TPS is bad.
Note
With some sensors, the resistance increases
above the 4-k
Ω
range when the throttle opens. If
this occurs, the meter autoranges to a higher
range, causing the bar graph to wrap. This does
not mean that the TPS is bad.
