Self-Test Mode on the LG FH296HDL23
This guide explains how to perform a self-test on LG washing machines. While in self-test mode, the washer performs a series of functions to aid the user or service person in finding the source of a technical problem. These tests evaluate most mechanical and electric components of the device, such as the drum motor, drain pump, and inlet valve among other things, and show diagnostic information on the LCD display.
Warning
The self-testing mode is intended to be used by technicians or service engineers. If your device is still under warranty, it might be a better idea to contact an authorized service centre.
Caution
Make sure that the wash drum is empty before entering self-test mode. The washing machine can disable the internal vibration sensor during the low speed spin test. Any unbalanced load in the drum can cause serious or permanent damage to the machine.
Entering Self-Test Mode
Make sure that the drum is empty, the door is closed, and the machine is powered off. Press and hold the SPIN and TEMP buttons. While keeping them depressed, press the power button. The machine will emit 3 beeps, and all LEDs will light up to indicate that it's in self-test mode.
Note
The actual name of the button can vary between models or the region it's sold in, however the button position is usually the same. The key combination above is valid for the LG FH296HDL23 front loading washing machine.
Testing Procedure
After entering self-test mode, press the ⏯ button to start the first test. Press it again to advance to the next test. After all tests are completed, the next press of the ⏯ button will play the end chime and power off the washing machine. The following table shows the list of tests, which are described in more detail later.
| Times ⏯ pressed | Test | LCD Status |
|---|---|---|
| 0 | All lights turn on (standby mode) | EEPROM checksum |
| 1 | Clockwise tumble | Drum RPM |
| 2 | Low speed spin | Drum RPM / 10 |
| 3 | High speed spin | Drum RPM / 10 |
| 4 | Pre-wash inlet valve | Water level frequency |
| 5 | Hot water inlet valve (main wash inlet valve for incompatible models) | Water level frequency |
| 6 | Main wash inlet valve | Water level frequency |
| 7 | Counter clockwise tumble | Drum RPM |
| 8 | Heater (3 sec) | Water temperature |
| 9 | Drain pump | Water level frequency |
| 10 | End of test, power off | Blank |
If the washing machine detected any errors during testing, it will show the error codes on the LCD display after testing is finished.
Tests
Standby mode (⏯ x 0)
Immediately after entering self-test mode, all LED indicators on the machine will light up. This is a good time to check if any of the indicators are faulty. The LCD display shows the internal EEPROM checksum, which can be used to verify the model number and firmware present. For FH296HDL23, the display cycles between 1B:17, 1U:03, 1E:03.
Clockwise tumble (⏯ x 1)
This test spins the drum clockwise at about 45 RPM, which is the standard during normal operation. The motor initially ramps up to around 110 RPM, then slows gradually to 45 RPM. The measured RPM is shown on the LCD display. A value between 40 and 50 is considered acceptable.
Low speed spin (⏯ x 2)
This test starts the drain pump, and ramps up the drum gradually to 600 RPM. The current RPM is shown on the LCD display as a factor of 10. So a value of 23 indicates 230 RPM. When the motor reaches the maximum speed for this test, the display should have the value 60.
High speed spin (⏯ x 3)
This test increases the spin speed to the maximum, in this case 1200 RPM. Just like the previous test, add a 0 to the number displayed on the LCD to get the actual RPM.
Pre-wash inlet valve (⏯ x 4)
This test first stops the spinning drum, then opens the pre-wash inlet valve to start filling the drum. The display shows the output of the internal water level sensor. The value shown on the display is the water level frequency as a factor of 10-1 kHz. For an empty tub, the value should be 255 (25.5 kHz), and start decreasing as the tub fills with water. A tub full of water should show a frequency of about 214. To read more about how this frequency is calculated, click the block below.
How LG washing machines detect water level
LG washing machines use a frequency measurement method instead of the more common air pressure tube method used by other brands. This system has a coil attached to a diaphragm inside the washing machine tub. As the water level rises and falls, the diaphragm moves up and down, causing the coil to also move. This movement of the coil changes the resonant frequency characteristics of an oscillator circuit that the coil is part of. The main control board in the washing machine measures this changing frequency as the water level changes. So in essence, instead of measuring air pressure changes due to water level like other brands, LG monitors how the oscillating frequency of this coil circuit changes based on the diaphragm's vertical position, which correlates to the water level in the tub.
Hot water inlet valve (⏯ x 5)
This test closes the pre-wash inlet valve and opens the hot water inlet valve. The display shows the water level frequency just like the previous test.
Note
For models without a hot water inlet, this test opens the main wash inlet valve instead.
Main wash inlet valve (⏯ x 6)
This test closes the hot water inlet valve and opens the main wash inlet valve. For models without a hot water inlet, this test is the same as the last test. The display shows the measured water level frequency.
Counter clockwise tumble (⏯ x 7)
This test closes all inlet valves, and spins the drum counter clockwise at 45 RPM. Just like the first test, it ramps up initially, then gradually slows down. The LCD display shows the current RPM.
Heater (⏯ x 8)
This test turns on the heater for three seconds, then turns it off. The display shows the measured water temperature in degrees Celsius. The washer sits idle after three seconds until you advance to the next test.
Drain pump (⏯ x 9)
This test activates the drain pump and starts draining the water. The LCD display shows the water level frequency, which should rise gradually up to 255 when the drum is empty. The drain pump will not turn off by itself during this test.
Power off (⏯ x 10)
The LCD display and all indicator lights turn off, and the washing machine plays the end-of-cycle chime to indicate that the self-testing sequence is complete. If any errors were detected during the self-testing process, they are displayed here.