Bosch SHU53 - Page 8

BA Page C-2
SHU/SHI/SHV Dishwasher Quick Check Chart
1
st
Edition/Revision 0-A Tuesday, May 11, 1999
To check Measure If yes If no
ü
üü
ü Heater /flow
switch
/Hi-
Limit
thermostat
(185
o
F)
ü
üü
ü Current through hot
wire into dishwasher –
should be 10.5-11 A
(amps).
ü
üü
ü Heater/flow switch/Hi-
Limit thermostat are
OK.
ü
üü
ü Test each part, turn off
dishwasher and
replace defective part.
HINT: The resistance of
heater is ≈ 11 Ω, Hi-Limit
thermostat is
≈ .3 Ω & flow
switch is ≈ .4 Ω. To measure
flow switch resistance,
remove microswitch & close
its contacts.
HINT: The NTC and Hi-Limit
(185
o
F thermostat) are
changed as a unit. Must pull
out dishwasher and remove
or block up tub to replace it.
HINT: Don't pull out
dishwasher and remove tub
for initial checking – only
when you're certain one of
these parts has failed.
HINT: Start test program
(SHU/I models) and skip
"draining" and "Aqua Sensor
Calibration" until water has
finished filling. When heater
comes on, measure current.
Skip "heating & circulating"
once you've measured
current to save time.
HINT: Must pull out
dishwasher and remove or
tilt/block up tub to replace
parts. Bring all three parts
before disassembling
dishwasher and test each
part separately.
HINT: The Hi-Limit
thermostat (185
o
F) is a bi-
metal self-resetting
thermostat.
ü
üü
ü NTC
(temperature
probe)
ü
üü
ü At control module,
measure resistance
between two brown
wires at left of right
harness (≈ 55 kΩ at
room temperature
(72
o
F)).
ü
üü
ü NTC probably is OK. ü
üü
ü Turn off dishwasher
and replace NTC.
HINT: Make sure water in
sump has cooled to room
temperature before
measuring resistance.
HINT: The NTC and Hi-Limit
(185
o
F thermostat) are
changed as a unit. Must pull
out dishwasher and remove
or block up tub to replace it.
ü
üü
ü Water level
switch
ü
üü
ü After water fills, turn off
dishwasher and
measure (SHU/I
models) between white
wire at left of 3
rd
harness from left and
2
nd
blue wire from left of
4
th
harness from left (≈
.4 Ω).
ü
üü
ü Water level switch is
OK.
HINT: For SHV models,
measure between white wire
at right of 1
st
harness & white
wire at left of 4
th
harness.
ü
üü
ü Turn off dishwasher
and replace water
level switch.
HINT: Must pull out
dishwasher and remove left
side panel to access water
level switch.
ü
üü
ü Float switch
ü
üü
ü Resistance between
white wire to water
valve and white wire
either at right of on/off
switch harness (SHU/I
models) or at left of 4
th
harness (SHV models)
(≈ 4Ω).
ü
üü
ü Float switch and water
valve probably are OK.
ü
üü
ü Test float switch and
water valve, turn off
dishwasher and
replace whatever part
was defective.