Activating Service Diagnostic Mode; Diagnostic Guide - Maytag MHW9000YW0 Mode D'emploi

FOR SERVICE TECHNICIAN'S USE ONLY
ABBREVIATIONS
CCU: Central Control Unit
EB: Expansion Board
IF: Interference Filter
MCU: Motor Control Unit
UI: User Interface (center/modifier PCBs
& housing)

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?
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, pin insertion, 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.
PAGE 4
SERVICE DIAGNOSTIC MODE
These tests allow service personnel to test
and verify all inputs to the machine control
electronics. You may want to do a quick and
overall checkup of the washer with these tests
before going to specific troubleshooting tests.

ACTIVATING SERVICE DIAGNOSTIC MODE

1. Be sure the washer is in standby mode
(plugged in with all indicators off).
2. Select any three (3) buttons (except
POWER) and follow the steps below, using
the same buttons.
Within 8 seconds,
• Press and Release the 1st selected button,
• Press and Release the 2nd selected button,
• Press and Release the 3rd selected button;
• Repeat this 3 button sequence 2 more times.
3. If the key sequence was entered successfully,
the language selection screen is displayed.
4. Select the desired language—choices are:
English, French, and Spanish.
5. The following screen warns that this area is
for service technicians only.
• Pressing "Exit" returns to original screen.
• Pressing "Enter" continues to DIAGNOSTIC
HOME screen. See Figure 3, page 5. It
may take a few seconds for the Diagnostic
Home Screen to appear.
NOTE: Service Diagnostic mode will time out
and return to standby after 5 minutes of user
inactivity.
EXITING SERVICE DIAGNOSTICS
Use either of the two methods below to exit
Service Diagnostics.
• Scroll down and select "Exit Diagnostics"
on the Diagnostics Home Screen.
• Press the "Back" button one or more times,
depending on location in Service Diagnostics.
DO NOT REMOVE OR DESTROY