Service Manual

TESTING
18” & 24” ADA Built-In Dishwashers
n
3-13
For Service Technician Use Only
Overow Switch
The overow switch is located under the tub and is aached to
the drip pan (see Figure 1).
Foam
Float
Overow
Switch
Figure 1 - Overflow Switch Assembly
The overow switch is a normally closed switch that is used to
detect a possible overow condion. If water drips onto the
STRIP CIRCUIT - OVERFLOW SWITCH
Figure 2 - Overflow Circuit
drip pan, the water will li the foam oat and open the switch.
This will signal the control to shut o the water inlet valve and
acvate the drain pump. An “E4” Overow Error Code will be
generated.
NOTE: If the overow switch is disconnected or open, the
dishwasher will not start a cycle or perform diagnoscs.
Test Procedure
This test will check the wiring to the Overow Switch, the
switch itself, and the control board. The following items are
part of the Overow circuit.
n Harness/Connecon
n Overow Switch
n Control Board
1. Unplug dishwasher or disconnect power.
2. Remove access panel. Remove control board cover to
access control board.
3. Lay the dishwasher on its back. Use a small at-blade
screwdriver to unclip snaps around the drip-pan. Pull
away drip-pan but keep oat switch harness connected.
4. Disconnect CN4 from the Control Board.
5. Check the overow switch—using an ohmmeter, measure
the resistance between CN4-2 and CN4-3 with the
overow switch closed/oat down (normal posion).
¾ If 3 ohms or less is measured, go to step 6.
¾ If an open circuit or high resistance is measured, check
connecons and harness connuity between the
control board and overow switch. If harness is good,
replace switch and retest.
6. Using an ohmmeter; measure the resistance between
CN4-2 and CN4-3 with the overow switch open/oat up.
¾ If reading is innite, go to step 7.
¾ If 3 ohms or less is measured, or oat/overow switch
is damaged, replace switch and retest.
7. If the preceding steps did not correct the overow switch
problem, replace the control board and retest.
8. Unplug dishwasher or disconnect power.
9. Reassemble all parts and panels.
10. Plug in dishwasher or reconnect power and run Service
Mode Test on page 2-3 to verify repair.
CONTROL BOARD
OVERFLOW SWITCH
CONTROL BOARD
CN4-2
CN4-3
Overow Switch (NC)
(IAQS)
GY
PL
(GND)
WARNING
Electrical Shock Hazard
Disconnect power before servicing.
Failure to do so can result in death or
electrical shock.
Replace all parts and panels before operating.