Hi. Wayne here from Sears PartsDirect.
Today we’re going to talk about what to do when you see an F90 error code on your
range.
You’ll see this code when you try to lock or unlock the oven door on a range with a
lock feature like this one.
The F90 code means the electronic oven control board detects a problem with the door lock
system.
The F90 code can appear when you try to start a self-clean cycle, which uses the door lock.
You might also see the F90 code when the self-clean cycle ends and the electronic control can’t
unlock the oven door.
In this troubleshooting video, we’ll examine the components in the door lock system to
find out which part has failed.
These include the control board, the wiring and the oven door lock motor assembly.
The oven door lock assembly includes the door lock motor and the door lock switch.
Let’s get started.
You need a nut driver to remove the range back panels and a multimeter to perform electrical
checks during this troubleshooting.
You may also need a Phillips screwdriver to disassemble parts for testing.
First, unplug the range and pull it out of the cabinet.
If you have a gas range, shut off the gas supply.
Remove the screws and pull off the top and the bottom back panels.
Check the wiring connections between the control board and the oven door lock assembly.
Reconnect any loose wires and repair any broken or damaged ones.
This simple step may fix your door lock problem and clear the F90 code.
If you find and fix a broken or disconnected wire, reassemble the range and restore power
to it.
You should hear the door lock motor run when you plug it in, while it finishes locking
or unlocking the door.
If the wiring connections between the control and the door lock assembly look okay, we’ll
check the door lock switch next.
The door lock switch rests against the cam and detects motor movement.
If the switch breaks and can’t detect cam movement, the range displays the F90 code.
To see if the switch or wiring is broken, we’ll check resistance through them.
Disconnect the wire harness plug with orange and gray wires from the control board—it’s
the orange and gray wires that connect to the door lock switch.
We’ll check the switch and its wiring with the switch arm in two different positions:
pushed in and extended.
With your multimeter set to measure ohms, touch one meter probe to the orange wire and
the other meter probe to the gray wire on the wire harness plug.
Now, reverse the position of the switch arm.
If the switch arm was extended for the first reading, use a screwdriver to press it in
during the second test.
If it was pushed in for the first test, remove the cam screw and pull off the cam to release
the switch arm for the second test.
Once you’ve reversed the position, touch one meter probe to the orange wire and the
other meter probe to the gray wire on the wire harness plug.
If the multimeter measures near 0 ohms with the arm pushed in and OL with the arm extended,
the switch and its wiring are okay.
You can skip to the next section of this video to check the door lock motor—just look for
the title slide that says Door Lock Motor Testing.
If the multimeter measures the same resistance regardless of arm position, it means that
either the switch is broken or the wiring failed.
To determine whether the switch or wiring is at fault, disconnect the wires from the
switch spades.
Repeat the resistance test with the arm pushed in and with it extended, by touching the meter
probes directly to the switch spades.
If the multimeter measures the same resistance through the switch spades regardless of arm
position, replace the switch.
But if the meter measures near 0 ohms with the arm pushed in and OL with the arm extended,
replace the wiring because you know the switch is okay.
If the oven door lock switch and its wiring are okay, check the oven door lock motor and
its wiring by measuring resistance through the brown and white motor wires that connect
to the control board.
The multimeter will measure about 2,000 ohms through the door lock motor and its wiring
if the motor works as it should.
If so, you’ve now ruled out the door lock switch, the door lock motor and the wiring
as causes for the F90 code.
By process of elimination, a failed control board is causing the F90 code, so replace
the control board.
Watch our video “Replacing a Range Oven Control Board” to learn how.
If the meter measures OL or near 0 ohms of resistance through the door lock motor wires,
unplug the brown and white wires from the motor and measure the resistance across the
motor spades.
If the multimeter doesn’t measure about 2,000 ohms on this test, replace the oven
door lock assembly because the motor is bad.
Watch our video “Replacing a Door Lock in an Electric Range” to learn how.
If the multimeter measures around 2,000 ohms of resistance through the door lock motor,
the wiring between the motor and the control board is damaged.
Check resistance between the ends of the brown wire and the ends of the white wire.
The multimeter will measure near 0 ohms of resistance if the wires are okay.
Repair or replace a wire if the multimeter measure OL.
Also check the resistance between the control board ends of the brown wire and white wire.
Make sure the opposite ends of those wires don’t touch each other or anything else.
The multimeter measures OL if the wires are sound.
If it measures 0 ohms or any resistance value other than OL, damaged wire insulation is
allowing the internal wire strands of the brown wire to touch strands of the white wire.
Find and repair the wire damage.
After you repair the wiring or replace the failed part, reassemble the range, plug the
power cord back in and slide the range back into the cabinet.
The code should disappear, and the door will finish locking or unlocking.
Unlock the door if it locked and reset the clock.
Well, I hope this video helped you out.
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