The Gas Sensor - KitchenAid KHMS105E Service Manual

The gas sensor is used during the "Sensor
Cook" operation of the oven. It is located
above the oven and is mounted on the left side
of the sensor cover. The sensor consists of
two circuits housed on a small microcomputer
board that is supplied with a current to keep it
heated. The sensor heat conductivity will vary,
SENSOR
SENSOR
BOARD

THE GAS SENSOR

WH
RD
YL
WHT
YEL
RED
depending upon the humidity of the oven.
Changing humidity conditions, due to the cook-
ing process within the oven cavity, causes a
difference in potential between these two cir-
cuits. This difference is monitored by the mi-
crocomputer during cooking, allowing the mi-
crocomputer to determine the proper cook
time.
NOTE: Always verify that the sensor cover is
not obstructed (proper air flow is passing over
the sensor), and that the fan motor is working
properly, before replacing the gas sensor.
1. Set the ohmmeter to the R x 1
scale.
2. Remove the 3-pin connector from
the control circuit board and mea-
sure the resistance between the:
a) Red & white wire terminals.
You should measure 20 Ω @
68˚F.
b) White & yellow wire terminals.
You should measure infinity.
3-6
TESTING