Program a Remote Key

Reviewed by the Service Reset editor · Updated August 18, 2026 · How we verify
Quick referenceToolsWorking key + spareTime~10 minMethodOn-board pairing sequence

These instructions apply to the Lexus GS Mk2 (S160) 1997-2005.
For other models, please choose your vehicle here.

The Lexus GS (1997–2005) — the S160 GS 300 / GS 430 — lets you program the key remote yourself using the classic Toyota/Lexus door-lock sequence — no diagnostic tool. It’s fiddly on timing, but genuinely owner-doable for adding a spare or re-pairing after a flat cell.

Lexus GS Mk2 — the vehicle covered in this guide.
Lexus GS Mk2. Photo by Dinkun Chen via Wikimedia Commons, licensed CC BY-SA 4.0.

First, a Few Checks

  • You can register up to 4 remotes.
  • Have all remotes you want to keep ready — ‘rewrite’ mode erases existing codes.
  • Fit a fresh cell first (a weak remote won’t pair).
  • The steps are time-sensitive (40-second and 3-second windows).

Entering Programming Mode

  1. Insert the key into the ignition and remove it again.
  2. With the driver’s door open and unlocked (other doors closed and locked), within 40 seconds press the door-lock switch 5 times (LOCK/UNLOCK at 1-second intervals).
  3. Close and open the driver’s door once, then within 40 seconds press the door-lock switch 5 times again.
  4. Insert the key and turn the ignition LOCK → ON → LOCK at 1-second intervals, repeating to select the mode:
    • Add a remote (keep existing): once
    • Rewrite (erase all, then add): twice
    • Confirm how many are stored: 3 times
    • Erase all (lost remote): 5 times
  5. Remove the key. Within 3 seconds the door locks cycle to confirm the mode is entered.

Registering the Remote

  1. Within 3 seconds, press the remote’s LOCK and UNLOCK buttons together for ~1.5 seconds, then release.
  2. Press the LOCK button on the remote (hold ~2 seconds) and release.
  3. The door locks cycle — that remote is registered. Repeat for any others.
  4. To finish, open the driver’s door or turn the ignition on.

If It Won’t Program

  • Keep to the timing — miss a window and you start over.
  • Fit a fresh cell — see our GS key-fob battery guide.
  • Use ‘add’ mode to keep your other remotes working.

Frequently Asked Questions

Can I program a Lexus GS (1997–2005) remote myself?

Yes — via the Toyota/Lexus door-lock sequence (key in/out, lock-switch 5×, door cycle, lock-switch 5×, ignition LOCK-ON to pick the mode, then pair the remote).

Will it erase my other remotes?

Only in ‘rewrite’ mode (ignition twice). ‘Add’ mode (once) keeps existing remotes.

How many remotes can I register?

Up to 4.

It won’t enter programming mode — why?

Almost always the timing; open the door, start again, and use a fresh cell.

Need a new cell first? See our GS key-fob battery replacement guide.

Independent guide — not affiliated with Lexus. Always follow your official service manual and safety precautions. Read our full disclaimer.

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