What causes LG Microwave AC1?

The Auto Cook button was pressed once, which selects Ac-1 (Bacon) on LG models that use this menu (LG owner's manual MFL71740601). Someone leaned on or wiped the touch panel and tapped Auto Cook by accident. A program was set up but START/Enter was never pressed, so Ac-1 is still waiting in the display. Rarely, a stuck or shorting key that keeps selecting a menu by itself; LG reports a key short as E10 or F3 instead, so a stray Ac-1 alone is not a confirmed keypad fault.

How do I fix LG Microwave AC1?

Press STOP/Clear to cancel. LG's manual uses STOP/Clear to stop the oven or clear all entries. If you do want bacon: lay 2 to 4 slices on a microwave bacon rack or a plate lined with paper towels, press + until the right amount shows, close the door and press START/Enter. For anything else, use Cook Time and Power Level to cook manually, or choose the right Sensor Cook, Auto Reheat or Auto Cook number from your manual's table. If the panel won't respond and Loc is showing, press and hold STOP/Clear for about 3 seconds to turn off the child lock (LG owner's manual). If Ac-1 keeps reappearing when nobody pressed Auto Cook, wipe the touch panel dry and unplug the microwave for a couple of minutes, then plug it back in. If the microwave runs (fan and light on) but food doesn't heat after you press START/Enter, check that the door closes firmly. LG's troubleshooting table lists an open door, unset cooking time or unplugged cord as reasons the oven won't start. Don't open the cabinet. Microwaves store a dangerous charge in the high-voltage capacitor even when unplugged.

When should I call a pro for LG Microwave AC1?

Ac-1 or other menu codes keep popping up by themselves after a reset and a dry panel: have the touch keypad and control checked. The microwave shows Ac-1, you press START/Enter and it runs without heating, or the turntable doesn't turn: that's not what Ac-1 means, so schedule LG service or a technician to check the door switches, fuse and high-voltage parts. You also see E or F codes, sparking, a burning smell, or a door that won't latch: stop using it and book a repair.

Code: AC1🔧 LG Microwave

LG Microwave Shows "Ac-1": Auto Cook Bacon Setting, Not an Error (What to Do)

Q: What does LG Microwave AC1 mean?

Ac-1 (often read as AC1 or AC-1) on an LG microwave is not a fault code. It's the first item on the Auto Cook menu, which LG's owner's manual lists as Bacon (2 to 4 slices). It shows up when the Auto Cook button has been pressed, on purpose or by a bump to the keypad. Press STOP/Clear to back out, or pick the amount with + and press START/Enter to cook bacon. If Ac-1 keeps appearing when nobody touched Auto Cook, or the microwave won't heat at all, that's a different problem worth a reset and then service. LG's owner's manual MFL71740601 (countertop models LMC0975, LMC1575 and MSWN1590L) explains that Auto Cook has preprogrammed settings for common foods. You open the door, press STOP/Clear, then press Auto Cook repeatedly until Ac-1 appears; the codes run from Ac-1 to Ac-7. Press + to set the amount, close the door and press START/Enter. In that manual's menu table, Ac-1 (and its sensor twin Sc-1) is Bacon, 2 to 4 slices; Ac-2 is fresh vegetables, Ac-3 frozen entree, Ac-4 frozen vegetables, Ac-5 oatmeal, Ac-6 potato and Ac-7 rice. Similar two-letter displays are also menu codes: Sc for Sensor Cook, Sr for Sensor Reheat and Ar for Auto Reheat. So seeing Ac-1 means the oven is waiting for you to confirm a bacon program, not reporting a failure. Menu numbers can differ by model, so check the Auto Cook table in your own manual. LG's real fault codes look different, such as E10 (key short), F3 (stuck key), F4 (humidity sensor) and F11 (inverter communication), and Loc means the child lock is on.

Reviewed 2026-10-26 · Based on 2 manufacturer & service sources

What the code means

LG's owner's manual MFL71740601 (countertop models LMC0975, LMC1575 and MSWN1590L) explains that Auto Cook has preprogrammed settings for common foods. You open the door, press STOP/Clear, then press Auto Cook repeatedly until Ac-1 appears; the codes run from Ac-1 to Ac-7. Press + to set the amount, close the door and press START/Enter. In that manual's menu table, Ac-1 (and its sensor twin Sc-1) is Bacon, 2 to 4 slices; Ac-2 is fresh vegetables, Ac-3 frozen entree, Ac-4 frozen vegetables, Ac-5 oatmeal, Ac-6 potato and Ac-7 rice. Similar two-letter displays are also menu codes: Sc for Sensor Cook, Sr for Sensor Reheat and Ar for Auto Reheat. So seeing Ac-1 means the oven is waiting for you to confirm a bacon program, not reporting a failure. Menu numbers can differ by model, so check the Auto Cook table in your own manual. LG's real fault codes look different, such as E10 (key short), F3 (stuck key), F4 (humidity sensor) and F11 (inverter communication), and Loc means the child lock is on.

Likely causes

The Auto Cook button was pressed once, which selects Ac-1 (Bacon) on LG models that use this menu (LG owner's manual MFL71740601)
Someone leaned on or wiped the touch panel and tapped Auto Cook by accident
A program was set up but START/Enter was never pressed, so Ac-1 is still waiting in the display
Rarely, a stuck or shorting key that keeps selecting a menu by itself; LG reports a key short as E10 or F3 instead, so a stray Ac-1 alone is not a confirmed keypad fault

Safe DIY checks

⚠ Before you start

Unplug the appliance or switch off its breaker before opening panels.

Press STOP/Clear to cancel. LG's manual uses STOP/Clear to stop the oven or clear all entries.
If you do want bacon: lay 2 to 4 slices on a microwave bacon rack or a plate lined with paper towels, press + until the right amount shows, close the door and press START/Enter.
For anything else, use Cook Time and Power Level to cook manually, or choose the right Sensor Cook, Auto Reheat or Auto Cook number from your manual's table.
If the panel won't respond and Loc is showing, press and hold STOP/Clear for about 3 seconds to turn off the child lock (LG owner's manual).
If Ac-1 keeps reappearing when nobody pressed Auto Cook, wipe the touch panel dry and unplug the microwave for a couple of minutes, then plug it back in.
If the microwave runs (fan and light on) but food doesn't heat after you press START/Enter, check that the door closes firmly. LG's troubleshooting table lists an open door, unset cooking time or unplugged cord as reasons the oven won't start.
Don't open the cabinet. Microwaves store a dangerous charge in the high-voltage capacitor even when unplugged.

🛠 When to call a pro

Ac-1 or other menu codes keep popping up by themselves after a reset and a dry panel: have the touch keypad and control checked.
The microwave shows Ac-1, you press START/Enter and it runs without heating, or the turntable doesn't turn: that's not what Ac-1 means, so schedule LG service or a technician to check the door switches, fuse and high-voltage parts.
You also see E or F codes, sparking, a burning smell, or a door that won't latch: stop using it and book a repair.

Parts that commonly fix it

Always match the part number to your exact model.

⚙

Microwave bacon rack

Optional. LG's manual suggests a microwave bacon rack (or a paper-towel-lined plate) for the Ac-1 Bacon program. Ac-1 itself doesn't mean anything is broken.

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⚙

Microwave touch control panel (keypad)

Only if a technician confirms the keypad is selecting menus on its own. Match your exact model number.

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Sources

Last reviewed 2026-10-26. Always confirm against the manual for your exact model number.

LG Microwave Shows "Ac-1": Auto Cook Bacon Setting, Not an Error (What to Do)

What the code means

Likely causes

Safe DIY checks

🛠 When to call a pro

Parts that commonly fix it

Microwave bacon rack

Microwave touch control panel (keypad)

Related codes

Sources