166 KENR9126
Troubleshooting Section
•
0535-04 Exhaust Gas Temperature Sensor voltage
below normal
Pull-up Voltage
The ECM continuously outputs a pull-up voltage
on the circuit for the sensor signal wire. The ECM
uses this pul
l-up voltage in order to detect an open
in the signal circuit. When the ECM detects the
presence of a voltage that is above a threshold on the
signal circ
uit, the ECM will generate an open circuit
diagnostic code -3 for the sensor.
If the senso
r is disconnected at the sensor connector,
the presence of pull-up voltage at the sensor
connector indicates that the wires from the sensor
connector
to the ECM are not open or shorted to
ground. If the sensor is disconnected at the sensor
connector, the absence of pull-up voltage at the
sensor con
nector indicates an open in the signal wire
or a short to ground. If the sensor is disconnected at
the sensor connector and the voltage at the sensor
connecto
r is different from pull-up voltage, the signal
wire is shorted to another wire in the harness.
g02193015
Illustration 62
Schem
atic for exha ust gas tem perature sensor
g01159881
Illustration 63
Typical exam ple of an exhaust gas temper ature sensor connector
(A) Sensor +5 Volt s upply
(B)Sensorreturn
(C) Sensor signal
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