Citroen C4 car unlocks, but will not start. battery seems ok.

You could check the fuses , there is a stop / start button fuse for instance . But it may only be a flat battery . If you can check / charge or jump start that would be best before getting too involved


Citroen C4 Picasso mk2 (from 2013) – fuse box diagram
Year of production: 2013, 2014, 2015, 2016

Fuse box under dashboard
The type of electrical of the vehicle depends on its level of equipment. To identify the type of electrical system on your vehicle, open the bonnet.

TYPE 1: electrical system does not have any fuses in front of the battery

TYPE 2: presence of an additional fusebox in front of the battery

Type 1 fuse box
Fuse box number 1
Fuse Ampere rating [A] Function
F8 5 Steering mounted controls
F18 20 Touch screen tablet, audio and navigation system, CD player, USB ports and auxiliary sockets (AUX)
F16 15 Front 12V socket
F15 15 Boot 12V socket
F28 5 START/STOP button
F30 15 Rear wiper
F27 15 Front screenwash pump, rear screenwash pump
F26 15 Horn
F20 5 Airbags
F21 5 Instrument panel
F19 5 Rain and shunshine sensor
F12 5 Keyless starting unit
F2 5 Manual headlamp adjustment control
Fuse box number 2
Fuse Ampere rating [A] Function
F9 15 Rear 12V socket


Type 2 fuse box
Fuse Ampere rating [A] Function
F3 3 START/STOP button
F6A 15 Touch screen tablet, audio and navigation system, CD player, USB ports and auxiliary sockets (AUX)
F8 5 Alarm
F9 3 Steering mounted controls
F19 5 Instrument panel
F24 3 Rain and sunshine sensor
F25 5 Airbags
F33 3 Memorisation of diving position
F34 5 Electric power steering
F13 10 Front 12V socket
F14 10 Boot 12V socket
F16 3 Map reading lamps in row 1 courtesy lamps
F27 5 Electronic gearbox gear selector
F30 20 Rear wiper
F38 3 Manual headlamp adjustmet control
Fuse box in engine compartment
Type 1 fuse box
Fuse Ampere rating [A] Function
F18 10 Right hand main beam
F19 10 Left hand main beam
Type 2 fuse box
Fusebox 1
The fusebox is place in the engine compartment near the battery (left-hand side).

Fuse Ampere rating [A] Function
F9 30 Motorised tailgate
F19 25 HIFI amlifier
F21 3 Hands-free starting reading unit
Fusebox 2
An additional fusebox is fitted in ftont of the battery (fot type 2).

Fuse Ampere rating [A] Function
F19 30 Front wiper slow/fast speed
F20 15 Front and rear screenwash pump
F21 20 Headlamp wash pump
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market..

Hi
Thanks. I will take a look. The battery is reading 12V. The central locking works, but the wing mirrors don't open,
best
Barry

A reading of 12v is a flat / low battery

https://footprinthero.com/lead-acid-battery-voltage-charts

was your issue ever fixed? I am having the exact same problem.

No update since posting Nov 28, 2022 (7 months ago)

Yes, eventually the garage admitted responsibility, and fixed it. They refused to tell us what they did.

Strange any for garage to do that without some reason . Should have insisted on an itemised invoice on paying .

I have the same problem.
Central locking works, wing mirrors won`t open, touch screen not coming on, engine not switching on (noticed brake pedal quite firmer than usual)
Tried switching the radio on, screen and radio came on for about 3 minutes then stayed off.
Top panel is only displaying the "press brake pedal to start" message.
Fitted a new battery with same results.

A few months before this happened, I was getting phantom error messages. Dealer fixed damaged wiring by the rear offside wheel somewhere.

Any help or suggestions would be brilliant, thanks.
David
Citroen C4 Picasso Blue HDI Exclusive 1.6 2015 Automatic

did you sort this im having very similar problem there is a smell of wire burning as well
Citroen C4 Picasso Blue HDI Exclusive 1.6 2015 Automatic

A dud battery can give you an acrid smell from the gases which is often mistaken for burning .Also check battery terminals and all earths .