Whirlpool MAT20CS Manual page 17

THERMISTOR RESISTANCE
Approx. Temperature
°C °F
0 32
5 41
10 50
15 59
20 68
25 77
30 86
35 95
40 104
45 113
50 122
55 131
60 140
65 149
 I f the resistance is within the range shown in the table,
go to step 6.
 I f the resistance is infinite or close to zero, replace the
temperature thermistor assembly.
NOTE: Most thermistor errors are a result of the resistor being
out of range. If the temperature thermistor malfunctions, the
washer will default to pre-programmed wash settings.
6. If the thermistor is good, replace main control and run
Calibration Mode (see page 4). Perform Quick Overview
Test on page 8 to verify repair.
TEST #6: Water Level
This test checks the water level sensing components. Depending
on the model, the washer will have either an on-board pressure
transducer or a separate pressure switch. NOTE: Usually, if the
pressure transducer or pressure switch malfunctions, the washer
will generate a long fill or long drain error.
1. Check the functionality of the pressure transducer or
pressure switch by running a small load cycle. The valves
should turn off automatically after the correct water level in the
tub. The following steps assume that this step
was unsuccessful.
2. Drain the tub until all water has been removed.
3. Unplug washer or disconnect power.
L1
Main Control
K7
J7-1
Drain Pump Motor Relay
DO NOT REMOVE OR DESTROY
FOR SERVICE TECHNICIAN'S USE ONLY
Approx. Resistance
(K )
163
127
100
79
62
50
40
33
27
22
18
15
12
10
Drain Pump Motor
J16-3 Pin 1
Motor
Motor Resistance 111 to 137 ohms
Figure 6 - Drain Pump Strip Circuit
4. Remove console to access controls.
5. Check hose connection between the pressure transducer
or switch and the pressure dome attached to the tub.
6. Check to ensure hose is routed correctly in the lower cabinet
and not pinched or crimped by the back panel.
7. Verify there is no water, suds, or debris in the hose or dome.
Disconnect hose from main control or pressure switch and
blow into hose to clear water, suds, or debris.
8. Check hose for leaks. Replace if needed.
9. If the preceding steps did not correct the problem, go to
step 10 if troubleshooting a pressure switch, or step 11 if
troubleshooting an onboard pressure transducer.
10. Pressure Switch Only:
a. Remove the pressure hose from the switch.
b. Place the leads of an ohmmeter across connector J4,
pins 1 & 3 of the main control. Blow into the pressure switch
inlet. The pressure switch contact should close and show
continuity.
 I f there is no continuity, check the harness and connections
between the pressure switch and J4 on the main control.
If OK, replace the pressure switch.
 I f there is continuity, reconnect hose to pressure switch
and continue to step 11.
11. Replace the main control and run Calibration Mode (see
page 4). Perform Quick Overview Test on page 8 to verify
repair.
TEST #7: Drain Pump
Perform the following checks if washer does not drain.
NOTE: Refer to Figure 6, "Drain Pump Strip Circuit" for tests
and measurements.
IMPORTANT: Drain water from tub before accessing bottom
of washer.
1. Check for obstructions in the usual areas. Clean and then
perform step 2.
Shifter Assy
Pin 2 Pin 1 Pin 2
Main Control
J16-2 J7-3
N
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