Diagnostic Guide; Activating Service Diagnostic Test Modes; Diagnostic Test Modes - Whirlpool MVWC450XW4 Manual

FOR SERVICE TECHNICIAN'S USE ONLY

DIAGNOSTIC GUIDE

Before servicing, check the following:
Make sure there is power at the wall outlet.

Has a household fuse blown or circuit breaker

tripped? Was a regular fuse used? Inform
customer that a time-delay fuse is required.
Are both hot and cold water faucets open

and water supply hoses unobstructed?
Make sure drain hose is not sealed into

drain pipe, and that there is an air gap for
ventilation. Ensure drain height is between
39" (991 mm) and 8' (2.4 m) above the floor.
All 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.
Resistance checks must be made with

washer unplugged or power disconnected.
IMPORTANT: Avoid using large

diameter probes when checking harness
connectors as the probes may damage
the connectors upon insertion.
Check 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.
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 – 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. You may want to do a quick and overall
checkup of the washer with these tests before
going to specific troubleshooting tests.
PAGE 2
ACTIVATING THE SERVICE

DIAGNOSTIC TEST MODES

1. Be sure the washer is in standby mode
(plugged in with all indicators off).
NOTE: After initial power is applied, wait 10
seconds before activating Service Diagnostic
Test Modes.
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.

RESET - Rotate cycle selector knob
L
counterclockwise one or more clicks
to clear sequence.

a. Rotate cycle selector knob clockwise
R
one click and wait ½ second.

b. Rotate cycle selector knob clockwise
R
one click and wait ½ second.

c. Rotate cycle selector knob clockwise
R
one click and wait ½ second.

d. Rotate cycle selector knob
L
counterclockwise one click and
wait ½ second.

e. Rotate cycle selector knob
R
clockwise one click.
 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:
Fill 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.
DO NOT REMOVE OR DESTROY
= ON = OFF
0.5 Seconds ON
Rinse Spin Done
0.5 Seconds OFF