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Error code reference

LG Refrigerator Error Code tt

Water tank not assembled correctly or water tank hall switch abnormal (lead wire, hall switch, or Main PCB…

LG codesLG refrigerator codes

Water tank not assembled correctly or water tank hall switch abnormal (lead wire, hall switch, or Main PCB defective).

First step from the service manual

Check water tank assembly and hall switch connection.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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  • Wiring diagram references and connector pinouts from the OEM service manual
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What tt means on a LG refrigerator

The tt error code on an LG refrigerator indicates a problem with the water tank assembly or the hall switch associated with it. The hall switch is a magnetic sensor that detects whether the water tank is correctly seated in its position. When the refrigerator cannot confirm proper tank placement through this sensor, or when the sensor itself fails to send a valid signal to the main PCB, the tt code is triggered. This error is specific to models equipped with an internal water tank system.

The fault can originate from three distinct points in the circuit: the physical assembly of the water tank, the lead wire connecting the hall switch to the control board, or the hall switch component itself. If the tank is even slightly out of position, the magnet that activates the hall switch may not align correctly, preventing the switch from closing and sending the proper signal. A damaged or pinched lead wire will interrupt the signal path entirely, mimicking a failed switch.

The main PCB is also listed as a potential source of this fault, making it the last component to suspect after confirming the tank, lead wire, and hall switch are all in good condition. Diagnosis should begin with a physical inspection of the water tank installation, followed by checking the hall switch connector and continuity of the lead wire. Replacing the hall switch is a relatively straightforward repair if the wiring checks out, while a main PCB fault is considerably more involved and costly.

Source: manufacturer service documentation.

Common causes of tt

  1. 01

    Water tank not fully or correctly seated

    Wiring / connection

    If the water tank is not pushed completely into its housing, the hall switch magnet will not align with the sensor and the tt code will appear. Remove the tank and firmly reinstall it, ensuring it clicks or locks into position.

  2. 02

    Damaged or disconnected lead wire

    Wiring / connection

    The lead wire connecting the hall switch to the main PCB can become pinched, frayed, or disconnected over time. Inspect the wire harness from the hall switch back to the board for visible damage or a loose connector.

  3. 03

    Faulty hall switch

    Part replacement

    The hall switch itself can fail, meaning it no longer sends a signal to the PCB even when the tank is correctly positioned. A failed hall switch will need to be replaced to resolve the error.

  4. 04

    Main PCB defective

    Part replacement

    If the water tank, lead wire, and hall switch all check out correctly, the main PCB may be failing to read the hall switch signal. This is the least common cause and should be diagnosed only after ruling out all other possibilities.

See the test procedure for each cause

Frequently asked questions about tt

What does tt mean on a LG refrigerator?
The tt error code on an LG refrigerator indicates that the water tank is either not assembled correctly or the hall switch that detects the tank position is not functioning properly. The fault can involve the tank itself, the lead wire to the sensor, the hall switch, or in rarer cases the main control board. The refrigerator displays this code when it cannot confirm the water tank is properly seated and detected.
How do I fix the tt error code on my LG refrigerator?
Start by removing the water tank and reinstalling it firmly to ensure it is fully seated. If the error persists, inspect the lead wire and connector for the hall switch for any visible damage or loose connections. If the wiring looks intact, the hall switch itself may need to be tested and replaced. If all components check out, a qualified technician should evaluate the main PCB.
Will resetting my LG refrigerator clear the tt error code?
A reset may temporarily clear the tt code from the display, but it will return if the underlying cause is not addressed. If the water tank simply shifted out of position, reseating it and resetting the unit may resolve the issue permanently. For hardware faults like a failed hall switch or damaged wiring, a reset alone will not fix the problem.
Is the tt error code on my LG refrigerator a safety concern?
The tt error is not typically a safety hazard. It relates to the water tank detection system and does not directly affect cooling or food preservation. However, depending on your model, it may prevent the water dispenser from functioning properly until the issue is resolved. Addressing the fault promptly is still recommended to avoid any secondary issues from ignored wiring problems.
How much does it cost to repair the tt error code on an LG refrigerator?
If reseating the water tank resolves the error, there is no parts cost involved. Replacing a hall switch or lead wire harness is generally a lower cost repair, with parts typically ranging from $15 to $60 and labor costs varying by region. A main PCB replacement is the most expensive scenario, with parts and labor potentially ranging from $200 to $500 or more depending on the model and service provider.

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