Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Suzuki Aerio L4-2.0LFACTORY OEM SERVICE PROCEDURE
Keyless Entry Transmitter: Testing and Inspection
Programming Transmitter Code
NOTE:
- Four transmitter codes can be programmed at the same time.
- When fifth transmitter code is programmed, the oldest one will be cleared automatically.
- Program transmitter code(s) to be used in total four times to delete programmed transmitter code(s).
If transmitter / door lock controller is replaced with a new one or additional transmitter(s) is necessary, program transmitter code(s).
1. Confirm that all doors are closed and ignition key is out of ignition key cylinder
2. Open driver side door.
3. Insert ignition key into ignition key cylinder within 10 seconds after step 2).
4. Remove ignition key from ignition key cylinder within 10 seconds after step 3).
5. Push and release driver side door switch (1) 3 times by hand within 20 seconds after step 4).
6. Insert ignition key into ignition key cylinder within 10 seconds after step 5).
7. Remove ignition key from ignition key cylinder within 10 seconds after step 6).
8. Press and hold "LOCK" and "UNLOCK" buttons (2) on transmitter (3) for 5 seconds or more within 20 seconds after step 6) and confirm that all doors are operated from lock to unlock.
9. Press "LOCK" or "UNLOCK" button (2) transmitter (3) within 5 seconds after step 8) and confirm that all doors are operated from lock to unlock.
With this process, transmitter code has been programmed.
10. If you want to program the additional transmitter, repeat the procedure from Step 1) through Step 9).
11. Make sure that keyless entry system properly operates by operating programmed transmitter(s).

NOTE:
- Four transmitter codes can be programmed at the same time.
- When fifth transmitter code is programmed, the oldest one will be cleared automatically.
- Program transmitter code(s) to be used in total four times to delete programmed transmitter code(s).
If transmitter / door lock controller is replaced with a new one or additional transmitter(s) is necessary, program transmitter code(s).
1. Confirm that all doors are closed and ignition key is out of ignition key cylinder
2. Open driver side door.
3. Insert ignition key into ignition key cylinder within 10 seconds after step 2).
4. Remove ignition key from ignition key cylinder within 10 seconds after step 3).
5. Push and release driver side door switch (1) 3 times by hand within 20 seconds after step 4).
6. Insert ignition key into ignition key cylinder within 10 seconds after step 5).
7. Remove ignition key from ignition key cylinder within 10 seconds after step 6).
8. Press and hold "LOCK" and "UNLOCK" buttons (2) on transmitter (3) for 5 seconds or more within 20 seconds after step 6) and confirm that all doors are operated from lock to unlock.
9. Press "LOCK" or "UNLOCK" button (2) transmitter (3) within 5 seconds after step 8) and confirm that all doors are operated from lock to unlock.
With this process, transmitter code has been programmed.
10. If you want to program the additional transmitter, repeat the procedure from Step 1) through Step 9).
11. Make sure that keyless entry system properly operates by operating programmed transmitter(s).
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
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