Troubleshooting

104 RENR2696-01
Troubleshooting Section
i02270219
Analog Throttle Position
Sensor Circuit - Test
System Operat
ion Description:
Use this procedure if another procedure has directed
you here. Use t
his procedure if any of the following
diagnostic codes are active:
•
91-02 Throttl
e Demand Sensor erratic or
intermittent
•
91-03 Throttl
e Demand Sensor open circuit or
shorted high
•
91-04 Throttl
e Demand Sensor shorted low
•
774-02 Throttle Demand Sensor No.2 erratic or
intermitten
t
•
774-03 Throttle Demand Sensor No.2 open circuit
or shorted hi
gh
•
774-04 Throttle Demand Sensor No.2 shorted low
•
262-03 5V Sensor Supply Voltage more than
normal
•
262-04 5V Sensor Supply Voltage less than normal
The throttle
demand sensor is an Analog sensor and
this sensor is mounted on the throttle pedal. The
throttle demand sensor provides an output voltage to
the ECM. Thi
s sensor output voltage will vary with
the position of the throttle from 0.5 volts to 4.5 volts.
The throttle demand sensor is attached directly to the
throttle a
ssembly. Foot or hand operated versions of
the throttle assembly are also available.
The sensor
receives +5 volt power from the ECM.
The sensor will produce a voltage that will alter
betweenlowidleandhighidle.Thevoltageis
changed in
toathrottlepositionwithintherange0to
100 percent by the ECM.
The throt
tle demand sensor senses the speed
requirement from the throttle position. A second
throttle demand sensor may override this speed
requirem
ent from the first throttle demand sensor.
This override will be subject to an input from either
the SAE J1939 (CAN), or from the Set Speed Control.
The inpu
t status can be checked on the electronic
service tool Status Display Screen.
The system will check the switch position in relation
to the throttle
position signal when the idle validation
has been set for use. If the switch position and the
signal from the throttle demand sensor are valid then
the throttle w
ill operate as normal.