Maytag MTW6300TQ Bravos Service Manual page 76

TEST #5 Automatic Temperature Control
This test checks the water inlet valves, the
temperature sensor, and the machine/motor
control.
1. Check the valves by performing Test #2,
before continuing to the next step.
2. Ensure proper hose connections and that
household's hot water is present.
3. Plug in washer or reconnect power.
4. Remove all clothes from the machine.
5. Select POWER • wash cycle NORMAL
• Wash/Rinse Temp. WARM/COLD •
START.
6. After the tub fills and starts to wash, stop
the machine.
7. Measure the water temperature, and ver-
ify it is 85°±5°F (29°±3°C).
• If the water temperature is correct, ATC
is functional.
• If the water temperature is incorrect,
then go to step 8.
8. Unplug washer or disconnect power.
9. Access the machine/motor control as-
sembly. See Accessing & Removing the
Electronic Assemblies.
10. Remove the P9 connector, and using an
ohmmeter, measure the resistance be-
tween pins P9-1, and P9-3. Verify that
the resistance is within range as shown
in the following table:
THERMISTOR RESISTANCE
Temperature
40°F (4.4°C)
50°F (10°C)
60°F (16°C)
70°F (21°C)
80°F (27°C)
90°F (32°C)
100°F (38°C)
110°F (44°C)
120°F (49°C)
130°F (55°C)
140°F (60°C)
• If the resistance is not within this range,
go to step 11.
• If the resistance is within this range, go
to step 12.
Resistance ( )
Ω
26–27.5 k Ω
19–20.5 k Ω
15–15.7 k Ω
11.7–12.2 k Ω
9.1–9.5 k Ω
7.2–7.6 k Ω
5.6–5.9 k Ω
4.6–4.9 k Ω
3.6–3.8 k Ω
2.9–3.1 k Ω
2.4–2.6 k Ω
6-12
11. Using an ohmmeter, measure continuity
between all pins on the P9 connector and
the thermistor contacts.
• If there is continuity, replace the log
valve assembly.
• If there is no continuity, replace the up-
per harness.
12. The log valve and upper harness are
good. Replace the machine/motor con-
trol assembly. See Reinstalling the Elec-
tronic Assemblies.
TEST #6 Water Level and Pressure Trans-
ducer Calibration
This test checks the water level sensing com-
ponents, and calibrates the pressure sensor.
1. Unplug washer or disconnect power.
2. Access the machine/motor control as-
sembly. See Accessing & Removing the
Electronic Assemblies.
3. Check hose connection between the
pressure transducer on the machine/mo-
tor control and the pressure dome at-
tached to the tub. Check to ensure hose
is routed correctly in the lower cabinet
and not pinched or crimped by the back
panel.
4. Plug in washer or reconnect power.
5. Drain the tub until all water has been re-
moved from tub.
6. Remove all clothes from the machine.
7. Calibrate the pressure transducer:
• See Activation of Manual Diagnostic
Test Mode, and perform steps 1 and 2
until the display shows 00 and the Add
A Garment indicator LED is flashing.
• Press and hold the Cycle Signal button
until a single beep sounds, and the dis-
play shows Pt to indicate zero calibra-
tion has completed.
• Exit Diagnostic: Manual by pressing
PAUSE/CANCEL or POWER.