Start the Car With a Dead Key Fob Battery

When the remote on your Jeep Grand Cherokee (WL, 2022–Present) stops responding and the screen warns “Key Fob Not Detected,” the coin cell in the fob has usually gone flat. The fifth-generation Grand Cherokee uses Keyless Enter-N-Go, and the system is designed for this situation: a dead fob still unlocks the car and still starts the engine, because the chip is powered by the vehicle. Here is the full procedure and how to replace the cell.

Start the Grand Cherokee with a dead fob battery

An RFID reader built into the ignition switch picks up the fob’s passive chip at close range — no fob power required:

1. Sit in the driver’s seat, close the door and press the brake pedal firmly.
2. Turn the fob so its nose end — opposite the emergency key blade — faces the dash.
3. Hold that nose flat against the ENGINE START/STOP button.
4. Push the button through the fob. The Grand Cherokee reads the chip and cranks.
5. After it starts, the fob can go in the wireless-charge tray or console for the trip.

There’s no need to disassemble the button — the proximity read through the touching fob is the factory-intended backup.

Unlock the doors with the emergency key

The radio lock/unlock won’t work on a flat fob, so use the hidden blade:

1. Slide the release catch on the fob and pull out the emergency key blade.
2. On the driver’s door handle, prise off the small cap concealing the lock cylinder.
3. Insert the blade and turn to unlock.
4. Slide the blade back into the fob afterward.

Will the alarm sound?

If the security system is armed, opening with the blade can trigger the alarm. Sit in and complete the dead-fob start above — recognising a valid key clears it.

Replace the key fob battery

WL fobs use a 3-volt lithium coin cell — most take a CR2032, though some proximity fobs use the thicker CR2450. Check the old cell before buying:

1. Slide the emergency blade out first; the slot it leaves is your pry point.
2. Split the fob halves with a coin or small flat screwdriver.
3. Note the orientation, remove the old cell, and fit the new one positive (+) the same way up.
4. Snap the halves together, refit the blade, and test lock/unlock from a few steps away.

Frequently Asked Questions

Does my WL fob take a CR2032 or CR2450? Both are used across the range. Open the fob and read the print on the old cell — that’s the only sure way to know which yours needs.

Can I use the wireless charge pad to revive the fob? No — that pad charges phones, not the fob’s coin cell. You still need to swap the battery.

Do I keep holding the fob once it starts? No. The chip read happens once at start; then you can put the fob away.

The screen and dash are completely dead — is that the fob? No, that points to the car’s 12V battery. Jump start the Grand Cherokee, then retry.

Why does the fob keep going flat? Leaving it close to the parked car keeps it awake and drains it. Store it away from the vehicle overnight.

If a warning light stayed on afterward, look up the code on our sister site autodtcs.com.