Test #5: Moisture Sensor - Whirlpool 4.3 CU FT Service Manual

TEST #1: ACU Power Check
This test is used to determine if power is
present at the machine control electronics.
COMPONENT TESTING
This test assumes that proper voltage is
present at the outlet.
1. Unplug dryer or disconnect power.
WARNING
2. Check for appropriate line voltages at the
outlet: 240VAC (electric 2-phase) or 208VAC
(electric 3-phase).
If line voltage is present, go to step 3.
If line voltage is not present, check for
tripped circuit breaker or blown household
Electrical Shock Hazard
fuse. If CB (circuit breaker) is not tripped,
Disconnect power before servicing.
have customer check with qualified
Replace all parts and panels before operating.
electrician.
Failure to do so can result in death or
3. Remove top panel, left side panel, and
electrical shock.
console to access the machine electronics.
4. ACU VAC – With voltmeter set to AC,
connect black probe to ACU J13-2 (L2) and
TEST #5: Moisture Sensor (SEH)
red probe to J13-1 (L1). (See Figure 2.)
Plug in dryer or reconnect power.
This test is performed when an automatic cycle stops too
soon, or runs much longer than expected.
M – Motor Supply
NOTE: Dryer will shut down automatically after 4 hours and 10
minutes.
J4-1 L1 Motor
The following items are part of this system:
J4-2 L2 Motor
Part of Moisture System
FM – Fan
Harness/connection
J2-1 L1
J2-3 L2
Metal sensor strips
DP – Drain Pump
Appliance Control Unit (ACU)
J3-1 L1
J3-3 L2
CONNECTOR LOCATION (ACU TOP)
WI1 – MCU communication
WI2 – User
MOISTURE SENSOR
MOISTURE (HUMIDITY) SENSOR STRIP CIRCUIT
DP – Drain
FM – Fan
M – Motor
Figure 2 - ACU Connectors
& Pinouts
n
3-12 Whirlpool Compact Heat Pump Dryer
For Service Technician Use Only
WI2 – User Interface
J17-1 VPOS
J17-2 +5VDC
J17-3 WIDE
Heat Pump Dryer
J17-4 GND
ü
SEH – Moisture Sensor
ü
J11-1 Gnd
ü
J11-3 Moisture Sensor
IF – RFI
J13-1 L1
J13-2 L2
interface
Figure 1 - Moisture Sensor Connector (SEH)
pump
ACU
HUMIDITY
J11-1
SENSOR
supply
HUMIDITY
J11-3
SENSOR
Figure 2 - Moisture Sensor Strip Circuit
unplug connector J17 from the ACU and
connect black probe to ACU J17-4 (ground)
and red probe to J17-2 (+5VDC). Plug in
dryer or reconnect power.
NOTE: Refer to strip circuit below to diagnose moisture sensor.
1. Unplug dryer or disconnect power.
6. Unplug dryer or disconnect power. Unplug
2. Remove top panel, left side panel, and console to access
the machine electronics.
J7 and J6 from the ACU. Plug in dryer or
3. Access moisture sensor inside front of drum to verify
reconnect power and repeat step 5.
continuity between moisture sensor in drum and J11-3
(blue wire) pin on ACU. NOTE: You may need to clean
sensor strip in drum before testing.
¾ Verify continuity between J11-1 (green wire) pin on
ACU and ground screw on cabinet.
¾ Verify continuity across J11-1 and J11-3 connectors.
¾ If continuity is found in the steps above, proceed to
step 5. If no continuity, proceed to step 4.
7. Unplug dryer or disconnect power.
4. Remove front panel and check J11-3 wire connection to
Reconnect J7 and J6 to the ACU and unplug
moisture sensor in drum (connector is located below the
J17 from the ACU. Plug in dryer or reconnect
door opening between the front panel and bulkhead) and
J11-1 wire connection to cabinet. If still no continuity,
power and repeat step 5. Perform voltage
replace the main harness.
check inside header J17 on ACU, between pins
5. Reassemble all parts and panels.
2 & 4—DO NOT SHORT PINS TOGETHER.
6. Plug in dryer or reconnect power.
7. Run the moisture sensor diagnostic test (Service Test
Cycle step S04; see pages 3 and 4). If the moisture sensor
diagnostic test passes (no F03 error code), check the
HE – Heater (Condenser dryer)/
outlet thermistor: see TEST #4c, page 17.
Compressor (HP dryer)
¾ If the problem persists after replacing the moisture
Condenser dryer
sensor and thermistor, consider adjusting the dryness
J5-1 level (see TEST #5a: Adjusting Customer-Focused L2
Dryness Level).
J5-2 Heater 1
J5-3 Heater 2
8. If the preceding steps did not correct the problem, replace
the ACU.
WI1 – MCU Communication
J12-2 +12VDC
J12-3 IN/OUT
J12-4 GND
HX-SLE
SET1 SET2
HE – Heater/
Compressor
BU
MOV
G-Y
If +5VDC is present, unplug dryer or
disconnect power and go to step 8.
If +5VDC is not present, go to step 6.
If +5VDC returns, one of the thermistors
has shorted. To diagnose thermistors,
see TEST #4c, page 17.
If +5VDC is not present, go to step 7.
HP dryer
J5-1 L2
J5-2 Compressor
SEH
MOISTURE SENSOR
ISOLATED METAL STRIP
0 to 15 M Ω
IF – RFI
CHASSIS GND
DO NOT REMOVE OR DESTROY
HX-SLE – Heat
Exchanger Switch
and Level Switch
J8-1 Heat Ex 1
J8-2 Heat Ex 2
J8-3 Float 1
J8-4 Float 2
SET1 – NTC Air Channel
J7-1 NTC Air 1
J7-3 NTC Air 2
SET2 – NTC Heater
J6-1 NTC Heat 1
J6-3 NTC Heat 2