Test #12: Communication Between Ui And Acu (W12) - Whirlpool 4.3 CU FT Service Manual

(electric 3-phase).
If line voltage is present, go to step 3.
COMPONENT TESTING
If line voltage is not present, check for
tripped circuit breaker or blown household
fuse. If CB (circuit breaker) is not tripped,
have customer check with qualified
WARNING
electrician.
3. Remove top panel, left side panel, and
console to access the machine electronics.
4. ACU VAC – With voltmeter set to AC,
connect black probe to ACU J13-2 (L2) and
red probe to J13-1 (L1). (See Figure 2.)
Electrical Shock Hazard
Plug in dryer or reconnect power.
Disconnect power before servicing.
Replace all parts and panels before operating.
M – Motor Supply
Failure to do so can result in death or
electrical shock.
J4-1 L1 Motor
J4-2 L2 Motor
FM – Fan
J2-1 L1
J2-3 L2
DP – Drain Pump
J3-1 L1
CONNECTOR LOCATION (ACU TOP)
J3-3 L2
WI1 – MCU communication
WI2 – User
DP – Drain
FM – Fan
M – Motor
Figure 2 - ACU Connectors
USER INTERFACE STRIP CIRCUIT
& Pinouts
ACU
n
3-20 Whirlpool Compact Heat Pump Dryer
For Service Technician Use Only
WI2 – User Interface
J17-1 VPOS
J17-2 +5VDC
J17-3 WIDE
J17-4 GND
SEH – Moisture Sensor
J11-1 Gnd
J11-3 Moisture Sensor
IF – RFI
J13-1 L1
J13-2 L2
interface
pump
Figure 1 - User Interface Connector (W12)
supply
J17-1
VPOS
J17-2
VCC
J17-3
WIDE
GND J17-4
Figure 2 - User Interface Strip Circuit
6. Unplug dryer or disconnect power. Unplug
J7 and J6 from the ACU. Plug in dryer or
reconnect power and repeat step 5.
TEST #12: Communications Between
UI and ACU (W12)
7. Unplug dryer or disconnect power.
Reconnect J7 and J6 to the ACU and unplug
This is a test to perform when the UI turns on and the button
J17 from the ACU. Plug in dryer or reconnect
LEDs flash, but does not display the cycles and options and will
power and repeat step 5. Perform voltage
not turn off.
check inside header J17 on ACU, between pins
1. Remove top panel, left side panel, and console to access
the machine electronics.
2 & 4—DO NOT SHORT PINS TOGETHER.
2. Verify that the harness is in good condition and check
the UI and J17 connections; check for continuity. If no
continuity, replace the harness.
3. If the problem persists, replace the ACU.
HE – Heater (Condenser dryer)/
4. If the problem persists, replace the UI.
Compressor (HP dryer)
Condenser dryer
J5-1 L2
J5-2 Heater 1
J5-3 Heater 2
WI1 – MCU Communication
J12-2 +12VDC
J12-3 IN/OUT
J12-4 GND
HX-SLE
SET1 SET2
HE – Heater/
Compressor
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
IF – RFI
USER INTERFACE
UI-4 VPOS
DO NOT REMOVE OR DESTROY
UI-3
VCC
UI-2 WIDE
UI-1 GND
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