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.
2004 Nissan-Datsun Sentra SE-RFACTORY OEM SERVICE PROCEDURE
Electronic Key Battery Replacement: Notes
WARNING: This page is about a different car, the 2003 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.
- Remove the mounting screw on the back side of the electronic key, and insert a slotted coin into the emergency key slot. Twist the coin to separate the upper body from the lower body. Then take out the electronic key transmitter.
- Insert a slotted screwdriver wrapped with tape into the electronic key transmitter (A) and twist the screwdriver to disassemble the transmitter.
- During disassembly, be careful not to touch the board surface. Visually check the board for color change (bluish) and deposit.
- When replacing the battery, keep the electrode contact clear of foreign materials such as dust and grease.
- Replace the battery fixed on the lower body. Be sure to install new battery properly with the positive side facing the lower case.
- After replacing the battery, engage the tab on the side of the body while being careful not to pinch the rubber, and assemble the upper and lower bodies.
- While being careful of engagement between the upper and lower bodies at the end, assemble the electronic key transmitter, and tighten it with screws.
CAUTION:
During disassembly, do not impact the transponder on the lower body.
CAUTION:
CAUTION:
After replacing the battery, be sure to check that the door locking operates normally using the electronic key.
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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