Diagnostic Guide; Service Diagnostic Test Modes - Whirlpool MAT20CS Manual

DIAGNOSTIC GUIDE

Before servicing, check the following:
M ake sure there is power at the wall socket/outlet.

H as a fuse blown or circuit breaker tripped? Was a regular

fuse used? A time-delay fuse is required.
A re both hot and cold water faucets open and water supply

hoses unobstructed?
A ll tests/checks should be made with a VOM (volt-ohm-

milliammeter) or DVM (digital-voltmeter) having a sensitivity
of 20,000 Ω per volt DC or greater.
R esistance checks must be made with washer unplugged

or power disconnected.
I MPORTANT: Avoid using large diameter probes when

checking harness connectors as the probes may damage
the connectors upon insertion.
C heck all harnesses and connections before replacing

components. Look for connectors not fully seated, broken
or loose wires and terminals, or wires not pressed into
connectors far enough to engage metal barbs.
A potential cause of a control not functioning is corrosion

or contamination on connections. Use an ohmmeter to check
for continuity across suspected connections.
T here are some fault/error codes that put the washer out

of service. All LEDs (except Lid Locked) will be solidly lit.
DIAGNOSTIC LED – MAIN CONTROL
A troubleshooting tool has been implemented onto the main
control board—a diagnostic LED.
LED ON – The control is detecting correct incoming line voltage
and the processor is functioning.
LED OFF – No power to control or control malfunction. Perform
TEST #1: Main Control, page 12, to verify main control functionality.
LED Location
Figure 1

SERVICE DIAGNOSTIC TEST MODES

These tests allow factory or service personnel to test and
verify all inputs to the main control board. Utilize these
performance tests before continuing to specific component
troubleshooting tests.
2
FOR SERVICE TECHNICIAN'S USE ONLY
ACTIVATING THE SERVICE DIAGNOSTIC
TEST MODES
1. Be sure the washer is in standby mode (plugged in with all
indicators off).
There are two failure modes that will cause the washer to drain
for an extended period of time (5 mins.), after which the washer
control returns to standby mode and is ready to start the next cycle:
(1) F8E3 – OVERFLOW CONDITION
(2) F3E1 – PRESSURE TRANSDUCER (SENSOR) FAULT
Use the following steps to enter into Fault Code Display Mode,
view the fault code, and clear logged fault codes.
2. Perform the following sequence of movement using the cycle
selector knob.
NOTE: AFTER RESET, sequence "a" through "e" must be
completed within 6 seconds, stopping just briefly between each
click (resulting in the following sequence: Left - Right - Right -
Left - Right, as indicated below).
RESET – Place cycle selector knob pointer at 12 o'clock
position and wait 3–4 seconds before proceeding.

a. Rotate cycle selector knob counterclockwise one click.
L

b. Rotate cycle selector knob clockwise one click.
R

c. Rotate cycle selector knob clockwise one click.
R

d. Rotate cycle selector knob counterclockwise one click.
L

e. Rotate cycle selector knob clockwise one click.
R
 Successful activation of Diagnostic Test Modes will be
indicated by all status LEDs (except for Lid Locked)
flashing ON and OFF in half-second intervals.
NOTE: LED names may vary between makes and models.
Legend: = ON
In Soak/
Use Wash
Figure 2 - Status LEDs flashing ON and OFF
 If the status LEDs do not display as described above, the
sequence may not have been completed within 6 seconds.
Repeat step 2 to ensure this was not the cause. If still
unsuccessful, see Unsuccessful Entry, page 3.
= OFF
0.5 Seconds ON
Final
Rinse Spin Done
0.5 Seconds OFF
DO NOT REMOVE OR DESTROY