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 Mazda 6 L4-2.3LFACTORY OEM SERVICE PROCEDURE
Keyless Entry Transmitter: Testing and Inspection
TRANSMITTER BATTERY INSPECTION
CAUTION: Since the battery voltage does not drop fully if the button is pushed for only 4 seconds or less, it can not be properly examined to see whether it is good or bad. Always push the button for 5 seconds.
NOTE: A correct measurement cannot be obtained if the battery temperature is low. Make sure the battery is at 18 °C {64 °F} or more for at least 30 minutes before reinspecting if a measurement value is under the standard voltage.
1. Remove the transmitter cover.

2. Apply the ohmmeter leads to the positions as indicated in the figure.

3. While pressing the battery as shown in the figure, press the LOCK and UNLOCK buttons on the transmitter at the same time to start measurement of the voltage.
4. Release the buttons after 5 seconds.
5. Verify that the minimum voltage is the standard voltage or more for 10 seconds after starting measurement.
- If the voltage is under the standard voltage, replace the battery.
Standard voltage 2.7 V
CAUTION: Since the battery voltage does not drop fully if the button is pushed for only 4 seconds or less, it can not be properly examined to see whether it is good or bad. Always push the button for 5 seconds.
NOTE: A correct measurement cannot be obtained if the battery temperature is low. Make sure the battery is at 18 °C {64 °F} or more for at least 30 minutes before reinspecting if a measurement value is under the standard voltage.
1. Remove the transmitter cover.
2. Apply the ohmmeter leads to the positions as indicated in the figure.
3. While pressing the battery as shown in the figure, press the LOCK and UNLOCK buttons on the transmitter at the same time to start measurement of the voltage.
4. Release the buttons after 5 seconds.
5. Verify that the minimum voltage is the standard voltage or more for 10 seconds after starting measurement.
- If the voltage is under the standard voltage, replace the battery.
Standard voltage 2.7 V
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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