Test #5: Moisture Sensor - Whirlpool WED99HEDW0 Technical Education

FOR SERVICE TECHNICIAN'S USE ONLY
L1
CYCLE CONTROL UNIT

TEST #5: Moisture Sensor

Electrical Shock Hazard
Disconnect power before servicing.
This test is performed when an automatic
BK
P9-2
Replace all parts and panels before operating.
cycle stops too soon, or runs much longer
K1
Failure to do so can result in death or than expected.
TEST #5: Moisture Sensor
MOTOR RELAY
electrical shock.
NOTE: Dryer will shut down automatically
This test is performed when an automatic
after 4 hours and 10 minutes.
cycle stops too soon, or runs much longer
than expected.
The following items are part of this system:
TEST #5: Moisture Sensor
NOTE: Dryer will shut down automatically
L1
Part of Moisture System
after 4 hours and 10 minutes.
CYCLE CONTROL UNIT
This test is performed when an automatic cycle stops too
The following items are part of this system:
Harness/connection
soon, or runs much longer than expected.
Metal sensor strips
NOTE: Dryer will shut down automatically after 4 hours and 10
BK Part of Moisture System
minutes.
N.O.
Machine control electronics
The following items are part of this system:
RELAY K3
NOTE: Refer to strip circuit on page 20 Harness/connection
Part of Moisture System
to diagnose moisture sensor.
Metal sensor strips
Harness/connection
1. Activate the Loads Test mode. See Machine control electronics
Metal sensor strips
procedures on page 4.
NOTE: Refer to strip circuit on page 20
Machine control electronics
to diagnose moisture sensor.
2. Open the door. Using a wet cloth or one
finger, jointly touch both sensor strips.
1. Activate the Loads Test mode. See
NOTE: Refer to strip circuit below to diagnose moisture sensor.
CYCLE CONTROL UNIT
procedures on page 4.
If a repeating beep tone is heard and an
1. Activate the Loads Test mode. See procedures on page 5-3.
2. Open the door. Using a wet cloth or one finger, jointly alphanumeric number is displayed on the
2. Open the door. Using a wet cloth or one
COMPRESSOR
touch both sensor strips.
THERMISTOR
console, the moisture sensor passes the
finger, jointly touch both sensor strips.
¾ If a repeating beep tone is heard and an alphanumeric
test. Go to step 9.
number is displayed on the console, the moisture
If a repeating beep tone is heard and an
OUTLET
sensor passes the test. Go to step 9.
If a beep tone is not heard, or a repeating
alphanumeric number is displayed on the
THERMISTOR
¾ If a beep tone is not heard, or a repeating beep tone is
beep tone is heard before touching both
console, the moisture sensor passes the
heard before touching both moisture strips, continue
moisture strips, continue with step 3.
with step 3. test. Go to step 9.
NOTE: Overdrying may be caused by a short
If a beep tone is not heard, or a repeating
circuit in the sensor system.
beep tone is heard before touching both
MOTOR SENSOR STRIP CIRCUIT
moisture strips, continue with step 3.
3. Unplug dryer or disconnect power.
NOTE: Overdrying may be caused by a short
4. Remove top panel to access the machine
CYCLE CONTROL UNIT
circuit in the sensor system.
electronics.
3. Unplug dryer or disconnect power.
5. Access the moisture sensor wires
MOISTURE SENSOR
by removing the console and front panel.
4. Remove top panel to access the machine
Disconnect the 3-wire moisture sensor
electronics.
connector located below the door opening
5. Access the moisture sensor wires
between the front panel and bulkhead.
by removing the console and front panel.
6. Access the CCU and remove connector
Disconnect the 3-wire moisture sensor
P13 from the circuit board. Check the wire
connector located below the door opening
harness for continuity between P13 and the
between the front panel and bulkhead.
moisture sensor connector.
6. Access the CCU and remove connector
If there is continuity, go to step 7.
For Service Technician Use Only
WARNING
FOR SERVICE TECHNICIAN'S USE ONLY
FOR SERVICE TECHNICIAN'S USE ONLY
LBU LBU
P9-1
CENTRIFUGAL SWITCH
R
COM1
Electric Dryer
PK
P14-1
R-W
P14-3
BK Y-R
P13-1
MOV
NOTE: Over-drying may be caused by a short circuit in the
sensor system.
3. Unplug dryer or disconnect power.
4. Remove top panel to access the machine electronics.
5. Access the moisture sensor wires by removing the console
and front panel. Disconnect the 3-wire moisture sensor
connector located below the door opening between the DRIVE MOTOR
front panel and bulkhead.
6. Access the CCU and remove connector P13 from the
7. Measure the resistance across the
circuit board. Check the wire harness for continuity
outermost contacts of the connector that
between P13 and the moisture sensor connector.
4M
includes the two MOVs.
BU
¾ If there is continuity, go to step 7.
THERMAL
¾ If there is no continuity, replace the main harness.
PROTECT
7. Measure the resistance across the
7. Measure the resistance across the outermost contacts of
outermost contacts of the connector that
the connector that includes the two MOVs.
includes the two MOVs.
Electric
Dryer
ü
2M V
5M ¾ If a small resistance is measured, clean the two metal
ü
See Electric
ü
Motor
Dryer
Circuit
8. Measure the resistance across each of the
¾ If a small resistance is not measured, go to step 8.
ü
1M
3M 6M
8. Measure the resistance across each of the outermost outermost contacts and the center terminal
ü
contacts and the center terminal (ground connection).
R
(ground connection).
ü
ü
8. Measure the resistance across each of the
ü
outermost contacts and the center terminal
ü
(ground connection).
COMPRESSOR TEMP THERMISTOR
¾ If a resistance less than infinity is measured, replace
10K
9. If the moisture sensor diagnostic test passes,
9. If the moisture sensor diagnostic test passes, check the
outlet thermistor: TEST #4a, page 6-15.
check the outlet thermistor: TEST #4a, page 15.
10K
¾ If the problem persists after replacing the moisture
9. If the moisture sensor diagnostic test passes,
check the outlet thermistor: TEST #4a, page 15.
OUTLET TEMP THERMISTOR
10. If the preceding steps did not correct the problem, replace
the CCU.
10. If the preceding steps did not correct the
problem, replace the CCU.
TEST #5a: Adjusting Customer-
10. If the preceding steps did not correct the
MOISTURE SENSOR
Focused Dryness Level
problem, replace the CCU.
NOTE: If the customer complains about the
TEST #5a: Adjusting Customer-
clothes being less dry or more dry than desired
G-Y G-Y
and the moisture sensor passes TEST #5:
Focused Dryness Level
Moisture Sensor, step 2, the total dry time can
NOTE: If the customer complains about the
be lengthened or shortened by changing the
clothes being less dry or more dry than desired
CHASSIS GND
Customer-Focused Dryness Level from "1"
and the moisture sensor passes TEST #5:
(standard auto cycle) to a "2" (15% more drying
Moisture Sensor, step 2, the total dry time can
time), "3" (30% more drying time), "4" (15%
HybridCare™ Dryer with Heat Pump Technology
be lengthened or shortened by changing the
less drying time), or "5" (30% less drying time)
Customer-Focused Dryness Level from "1"
auto cycle.
CENTRIFUGAL
SWITCH
1/3 HP
W
MAIN
5M
3M 6M
START
If a small resistance is measured, clean the
two metal moisture strips inside the drum.
If a small resistance is measured after
cleaning, replace sensor harness.
If a small resistance is measured, clean the
If a small resistance is not measured,
two metal moisture strips inside the drum.
moisture strips inside the drum. If a small resistance is
V
go to step 8.
If a small resistance is measured after
measured after cleaning, replace sensor harness.
HEATER
cleaning, replace sensor harness.
If a small resistance is not measured,
go to step 8.
If a resistance less than infinity is
measured, replace the sensor harness.
the sensor harness.
V
If a resistance less than infinity is
Y
measured, replace the sensor harness.
If the problem persists after replacing the
sensor and thermistor, consider adjusting the dryness
level (see TEST #5a: Adjusting Customer-Focused moisture sensor and thermistor, consider
Dryness Level).
adjusting the dryness level (see TEST #5a:
Adjusting Customer-Focused Dryness Level).
If the problem persists after replacing the
moisture sensor and thermistor, consider
adjusting the dryness level (see TEST #5a:
Adjusting Customer-Focused Dryness Level).
BK R
MOV
G-Y
TESTING
W
2M
LBU
N.O.
BU
DOOR
SWITCH
1M
See Heater Circuit
HIGH LIMIT
THERMOSTAT
V
CYCLE CONTROL UNIT
COMPRESSOR
P14-2
THERMISTOR RTN
OUTLET
P14-6
THERMISTOR RTN
CYCLE CONTROL UNIT
P13-2
MOISTURE SENSOR RTN
P8-2
CHASSIS GND
n
6-15
N
W
L2
R