Whirlpool MAT20CS Manual page 14

Shifter Switch:
9. With a voltmeter set to DC, connect the black probe to
J2-3 (Circuit Earth) and red probe to J2-1 (Shifter Switch).
In manual test mode, switch between Spin and Agitate
modes. Voltage should toggle between 0 and +5 VDC.
SPIN = +5 VDC
AGITATE = 0 VDC
 If voltage corresponds to setting, go to step 10.
 If voltage does not switch, go to step 12.
Optical Sensor:
10. With a voltmeter set to DC, connect the black probe to J2-3
(Circuit Earth) and red probe to J2-4 (+13 VDC).
 If +13 VDC is present, go to step 11.
 If +13 VDC is not present, go to step 17.
11. Activate Tachometer Verification Mode from the Service
Diagnostic Test Modes (see page 5). Slowly turn the basket
by hand. The 4 status LEDs should illuminate one at a time
to represent basket RPM.
 If the tachometer is not verified, go to step 12.
 If the tachometer is verified, go to step 17.
12. Unplug washer or disconnect power.
13. Tilt washer back to access the bottom of the washer
and the drive motor area.
14. Visually check the electrical connections to the shifter.
 If visual check passes, go to step 15.
 If connections are loose, reconnect the electrical connections
and repeat step 1.
15. With an ohmmeter, check the harness for continuity between
the shifter and main control using the pinouts in the following
chart.
 If there is continuity, go to step 16.
 If there is no continuity, replace the lower washer harness and
repeat step 1.
L1
Main Control
K8
J7-1
Shifter Motor Relay
Circuit Earth
+13VDC
14
FOR SERVICE TECHNICIAN'S USE ONLY
J16-1
J2-3
J2-4
Figure 4 - Shifter Assembly Strip Circuit (Shifter Switch: Open = SPIN, Closed = AGITATE)
Shifter to Main Control & Drain Pump
Shifter Connector Pin 2 to Main Control J16-2
Shifter Connector Pin 3 to Main Control J16-1
Shifter Connector Pin 4 to Main Control J2-4
Shifter Connector Pin 5 to Main Control J2-3
Shifter Connector Pin 6 to Main Control J2-2
Shifter Connector Pin 7 to Main Control J2-1
16. Replace the shifter assembly.
a. Unplug washer or disconnect power.
b. Replace shifter assembly.
c. Reassemble all parts and panels.
d. Plug in washer or reconnect power. Run Calibration Mode
(see page 4) and perform Quick Overview Test on page 8
to verify repair.
17. If the preceding steps did not correct the problem,
replace the main control.
a. Unplug washer or disconnect power.
b. Replace the main control.
c. Reassemble all parts and panels.
d. Plug in washer or reconnect power. Run Calibration Mode
(see page 4) and perform Quick Overview Test on page 8
to verify repair.
TEST #3b: Drive System – Motor
This test checks the motor, motor relay, motor windings, wiring,
and start capacitor.
NOTE: Refer to Figure 5, "Motor Strip Circuit" on page 15 for
tests and measurements.
IMPORTANT: Drain water from tub before accessing bottom
of washer.
1. Check the motor and electrical connections by performing
the Gentle or Heavy Agitation test under Manual Overview
Test Mode on page 9. The following steps assume that this
step was unsuccessful.
2. Unplug washer or disconnect power.
3. Check to see if basket will turn freely.
 If basket turns freely, go to step 4.
 If basket does not turn freely, determine what is causing
the mechanical friction or lockup.
Shifter Assy
Motor Resistance 9 to 9.75 kΩ
Pin 2
Pin 3
Shifter
Motor
Pin 7
Shifter Switch
Pin 5 Pin 6
Optical
Sensor
Pin 4
Main Control
J16-2 J7-3
Shifter Position
J2-1
Input
J2-2
RPM Input
DO NOT REMOVE OR DESTROY
N