CH46

Suction Pipe Temperature Sensor Error

Home Appliance Error Codes LG Split AC

Can you still use it? With care until repaired

Who can fix it? Needs a technician

Typical repair time 30 minutes – 3 hours

Typical cost SAR 80 to 2,500

What it means

This code appears on LG inverter split air conditioners and on LG ducted and cassette units that use CH codes. It means the thermistor on the suction pipe returning to the compressor in the outdoor unit is giving an impossible reading because of an open or short circuit. The unit uses this reading to set the electronic expansion valve and protect the compressor, so the compressor normally stops until the sensor is fixed. The same code can mean something else on other brands.

Models covered: LG inverter split air conditioners (e.g. Dual Inverter) and LG ducted/cassette units that use CH codes; the code shows as CH plus a number on the display or as LED blinks.

Symptoms3

CH46 shows and cooling stops.
Unsteady cooling or frost on the large pipe may come before the code.
The code returns after every restart.

Possible causes5

Sensor slipped out of its holder on the suction pipe, or its insulation came loose.
Sensor damaged by moisture and condensation on the cold pipe.
Cut or corroded wire.
Loose or corroded connector on the outdoor PCB.
Faulty sensor input on the outdoor PCB.

How to diagnose5

Switch off the breaker for a few minutes, then restart.
The technician waits for the board to discharge, then checks the sensor mounting, insulation and wire on the suction pipe.
Measure the sensor resistance against the LG table.
Inspect the connector and its socket on the outdoor board.
If the sensor is good, check the sensor input on the outdoor PCB.

How to fix5

Refit the sensor in its holder and rewrap the insulation over it.
Repair the damaged wire and clean the connector.
Replace the suction pipe sensor or the outdoor sensor set.
Replace the outdoor PCB if the sensor is proven good.
Run the unit and confirm stable cooling without the code.

Repair cost

0–200

200–600

600–1,500

1,500+

In Saudi riyals; the highlighted part is the expected range for this fault.

Most cases need only a low-cost sensor; the top of the range covers a new outdoor PCB.

Prices are rough estimates including the part and the technician’s fee, and vary with brand, model and part source.
Prices last updated: September 2026

Frequently asked questions

Why does the suction pipe sensor matter?

It helps the unit set the electronic expansion valve and stop liquid refrigerant returning to the compressor, so the compressor will not run without a valid reading.

Could the cause be low refrigerant?

No. This code points to an electrical fault in the sensor. Low refrigerant has its own code, CH38.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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