These instructions apply to the Porsche 718 Boxster / Cayman 982 2016-Present. For other models, please choose your vehicle here.
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The Porsche 718 (982, 2016–Present) — Cayman and Boxster — keeps Porsche’s signature left-hand ignition: when the key-fob battery dies you slide the fob into the slot to the left of the steering wheel and twist, just as a metal key would have worked. The mid-engine 718 starts even with a completely flat coin cell.
Start the 718 with a dead fob
- Open the car with the emergency blade first (next section), then sit down and close the driver’s door.
- To the left of the steering wheel, pull out the dummy/blanking key if one occupies the slot. The PCM may show “turn to the left, pull out, insert key.”
- Push the flat face of the fob into the slot where the dummy key sat, until it seats; the back-up reader coil energises the chip.
- Press the brake pedal and twist the fob clockwise to start. The flat-four/flat-six fires and you can release.
If the dash says the key is not detected, push the fob fully and squarely home and try again — the inductive range is only about a centimetre.
Unlock the 718 with the emergency key blade
- Slide the catch on the fob and pull the metal emergency blade out.
- The driver’s door barrel hides under a cover on the handle; lever the cover off with the blade.
- Insert the blade and turn to unlock. The alarm may chirp until the immobiliser reads the chip at start-up.
Why the immobiliser still reads a dead fob
The coin cell powers only the keyless proximity broadcast and the remote buttons. Engine authorisation uses a passive RFID transponder powered inductively by the coil in the ignition slot — not by the battery. Seating the dead fob in the slot lets the 718 read the chip and start.
Replace the fob battery
The 718 fob uses one CR2032 3V lithium coin cell. Pull the emergency blade and use it to lever the battery cover off, or part the casing at the seam. Lift the old cell out, fit the new one + side up, and click the cover back. Remote and keyless functions return at once with no coding.
Frequently Asked Questions
What is the dummy key in the 718’s slot?
Cars with full keyless Entry & Drive ship with a plastic blanking key in the ignition slot. Pull it out and insert your fob in its place to start.
Where is the slot — column or console?
On the 718, like the 911, it is to the left of the steering wheel, not in the console. That left-hand ignition is a Porsche tradition.
Can I leave the fob in the slot while driving?
Yes. The fob can stay parked in the slot. To shut down, twist it back and the engine stops.
Why did the alarm sound when I used the blade?
A mechanical unlock reads as forced entry until the transponder is verified. The alarm cancels the instant the engine starts.
Is it the fob or the 12V battery?
If the cockpit stays dark when you open the door, suspect the car’s 12V battery rather than the coin cell. A weak cell only affects the remote.
If a warning light stayed on after the no-start, look it up on autodtcs.com to confirm it was just the fob rather than an immobiliser code.
Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.
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