Bosch Evolution 300 Series Service Manual page 13

Relay and 3OXJ &RQQHFWLRQV
RELAY AND PLUG CONNECTION LOCATIONS ON
300 SERIES GAS RANGE CONTROLS
Sensor
Lock Motor Switch
Lock Motor Switch & Door Switch
Door Switch
RELAY AND PLUG CONNECTION LOCATIONS ON
500 SERIES GAS RANGE CONTROLS
Convection Fan Motor
Sensor
Lock Motor Switch
Lock Motor Switch & Door Switch
Door Switch
The oven temperature is monitored by the Hlectronic Rven control
through the Wemperature Vensor located inside the oven cavity. The
sensor or RTD as it is sometimes called increases its resistance as the
surrounding air temperature increases. The oven control interprets any
increase in the resistance of the sensor circuit as an increase in oven
temperature. If the wires or harness connections between the control
and the sensor are loose or otherwise defective the resistance detected
by the control may be much higher than the actual sensor resistance. In
some cases this can cause a false error message to be displayed on the
control such as F10 or F30.
Bake
Broil
Before assuming that a sensor is defective test the sensor resistance
L1
N
through the wire harness that attaches to the control. Disconnect the
Motor Door Lock
wires from the control and test with an ohmmeter. Normal resistance
Oven Light
at room temperature is approximately 1091 ohms. If the resistance is
correct for the temperature listed in the chart below then the sensor is
good and should not be replaced.
The accompanying chart can be
used to test the resistance of the
oven temperature sensor probe.
For accuraWH testing use a high
quality thermometer or temperature
meter to determine actual oven
temperature before reading the
resistance of the probe.
Bake
Broil
L1
N
Motor Door Lock
Oven Light
Temperature Sensor Operation and Testing
Temperature (°F)
Probe circuit to case ground
RTD SCALE
Resistance (ohms)
32 ± 1.9 1000 ± 4.0
75 ± 2.5 1091 ± 5.3
250 ± 4.4 1453 ± 8.9
350 ± 5.4 1654 ± 10.8
450 ± 6.9 1852 ± 13.5
550 ± 8.2 2047 ± 15.8
650 ± 9.6 2237 ± 18.5
900 ± 13.6 2697 ± 24.4
Open circuit / Infinite Resistance
1:11