These instructions apply to the DS 7 Crossback Mk1 (X74) 2017-Present.
For other models, please choose your vehicle here.
The DS 7 Crossback (2018–Present) — DS Automobiles’ flagship SUV, including the E-Tense plug-in hybrid — comes with keyless entry and start as standard on most trims. When the fob coin cell dies, the doors ignore your hand and the START/STOP button reports “key not detected”. It feels like a flat car battery, but it is only the fob. The DS 7 key still holds a battery-free transponder the car reads at close range, so you can get in and start it.
Unlock with the emergency blade, hold the fob to the steering-column reader and press the button — the immobiliser reads the chip even with a dead cell. The steps below walk through it.
Start the keyless DS 7 Crossback with a dead fob
- Open the car with the emergency blade (next section), sit in the driver’s seat and shut the door so the cabin antenna can search for the key.
- Press and hold the brake pedal — on the E-Tense plug-in hybrid the same brake-and-button sequence applies.
- Press the START/STOP button once. The DS cluster shows “key not detected”.
- Hold the flat face of the fob against the steering column, on the reader pad just to the left of the START button, where the backup antenna sits.
- With the fob held there and the brake pressed, press START/STOP again. The immobiliser reads the passive chip and the engine starts, or the hybrid shows READY.
Unlock the doors with the emergency key blade
- Slide the catch on the fob and pull out the metal emergency blade.
- The DS 7 has flush, motorised flush door handles; on the driver’s handle, lever off the small cover at the rear end with the blade tip to expose the hidden lock cylinder.
- Insert the blade, turn to unlock, then refit the cover. The alarm may sound until the car recognises the key and starts.
Why this works — the immobiliser note
The DS 7 Crossback fob holds a battery-powered radio for hands-free entry and a passive RFID transponder powered wirelessly by the car. A flat coin cell disables only the radio; the transponder still answers the immobiliser when held against the column reader. That is exactly why holding the fob to the column starts the DS 7 with a dead battery.
Replace the fob battery
The DS 7 Crossback fob uses a single CR2032 3V lithium coin cell. Remove the emergency blade, then prise the back cover off where the DS logo badge sits — slide a flathead screwdriver under the edge and lever it up. Lift the old cell, fit the new one with the + face up, and refit the cover. A fresh CR2032 lasts two to three years; if keyless range has shrunk, change it before it leaves you holding the fob to the column.
Frequently Asked Questions
Does the DS 7 E-Tense use the same method? Yes. Hold the fob against the steering-column reader and press START/STOP with the brake down to bring the plug-in hybrid to READY.
Where exactly is the reader on the DS 7? On the steering column just to the left of the START button, where the ignition barrel would be on a non-keyless car. Hold the fob flat against it.
How do I reach the keyhole with the flush handles? Pop the small cover off the rear of the driver’s door handle with the blade tip; the lock cylinder is behind it.
What battery does the DS 7 fob take? A CR2032 lithium coin cell, accessed by levering off the DS-logo cover on the back of the fob.
The alarm sounded when I opened with the blade — is that normal? Yes. Mechanical entry trips the alarm by design and it silences as soon as the car reads the key and you start it.
If a warning light or fault code appeared with the key message, you can decode it on our sister site autodtcs.com.
Independent guide — not affiliated with DS. Always follow your official service manual and safety precautions. Read our full disclaimer.