These instructions apply to the Citroën C4 Mk2 (B71) 2010-2018.
For other models, please choose your vehicle here.
The 12 V battery on the Citroen C4 Mk2 (2010–2018) is in the engine compartment. Because the car’s BSI control unit must power down first, there is a short waiting step before you disconnect — skipping it can set faults.
How to disconnect and reconnect the Citroen C4 battery (2010–2018)
- Park on level ground, apply the parking brake and select neutral or Park. Note your audio security code.
- Close all the windows and doors, lock then unlock with the mechanical key, and remove the key from the ignition.
- Wait at least 4 minutes for the BSI to go to sleep before touching the terminals.
- Open the bonnet and disconnect the negative (−) terminal first, then the positive (+).
- To reconnect, fit the positive (+) first, then the negative (−), and tighten both clamps.
If you will be working near airbags or seatbelt pretensioners, wait a further 5 minutes after disconnecting before starting.
After reconnecting the battery
- Reset the date and time.
- Re-initialise the electric windows so one-touch works again.
- Re-synchronise the remote control and check it locks/unlocks the car.
Frequently asked questions
Why wait 4 minutes before disconnecting a C4 battery?
The BSI body computer needs time to shut down and save its data. Disconnecting too soon can corrupt settings and trigger faults.
Which terminal first?
Negative (−) off first when disconnecting, positive (+) on first when reconnecting.
If a warning light stays on after reconnecting, you can check the stored fault code on autodtcs.com.
Independent guide — not affiliated with Citroën. Always follow your official service manual and safety precautions. Read our full disclaimer.