C4gp 2008 all electrics died mid driving causing small accident 😳

[MrStrange]

Hi good morning guys, apologies for writing on a Sunday!

Citroen c4 grand picasso 2008
So 2 days ago I was about to reverse into a parking space, in which the car completely died, it bad a battery light on the dashboard


The car steering wheel locked and wouldn't move, the brake was rock solid and wouldn't push down, the handbrake also wouldn't work,

I had to basically sit there and crash into another car, smashing up all their bumper,

The car eventually started so I could reverse to see the damage, and managed to find the owner of the other car ( thankfully it was the Vet who fixed my dogs eye problem, so we've spoken on a number of occasions, and she's let me pay the repair bill privately!)

We had RAC come out ( 4 hours ) and they basically made us drive the car home, he checked the battery and alternator in which they are both working perfectly fine


Scared s**t to even take the kids in the car now, as if this happened at a higher speed,


For some reason the car diagnostic port will no longer read my diagbox vci, so I'm unable to check for any faults, ( I changed the fuse with no avail, so maybe a faulty vci all of a sudden )


I checked the fuses on the battery in which I found that there was no fuse F4 for the automatic gearbox actuator and ECU, and the F5 diagnostic socket fuse had a 5amp fuse instead of a 15amp


Would really appreciate any help please, the car is currently driving perfectly fine, but it worries the hell out of us, and it may have to be scrapped

Thank you for your time

[GiveMeABreak]

This doesn't make sense to me - there will always be braking as it's a mechanically operated pedal and there is a vacuum reserve - but even without the assistance there should be braking ability to stop the vehicle based on the pressure you apply to the braking pedal.

The power steering systems on these use an electro pump, and if the engine stops steering is still supplied directly from the battery - so if you have an issue where there is no electrical power, then you will have no assistance.

So you must of had a catastrophic failure of the power supply - either the electrical connections to / from the battery or supplies unit ' fusebox / alternator to cause this sort of issue.

If you are going to keep it, I would get it to Citroen for a proper diagnosis to be honest.

[white exec]

Second that. You were lucky only to have had a low-speed incident.
In this case, Citroen should do the investigation, and come up with a definitive diagnosis/fix.

[Freebird]

Unfortunately, you're not alone.
Last November, with my Grand Picasso 1.6 HDi CMP-6 with 185,000 km, fully serviced and in perfect condition, I experienced a similar issue.

While I was on a narrow and busy street, everything suddenly shut down—complete blackout. The gearbox was stuck in third gear, no hazard lights, nothing, as if the battery were completely dead.
I had to push the car with the gear engaged!

After opening the hood, I disconnected and reconnected the positive cable, and magically the car shifted into neutral (right on my knees), and everything turned back on. I restarted the car as if nothing had happened, but after 200 meters, everything shut down again. I fiddled with the cables above the battery, and everything came back to life. Of course, the clock and settings were reset.

The voltmeter was showing a fluctuating reading between 13.6 and 14.6 volts.

Then, no problems at all—until the other night. The car shut down completely in the middle of a roundabout on an uphill slope, stuck in fourth gear. I spent 30 minutes waiting for a tow truck with my foot on the brake pedal.

Now the car is at the mechanic, and they still don't know what the issue might be!

MrStrange, Can I ask if and how you managed to resolve your issue?

Thanks!

[GiveMeABreak]

This sort of failure is likely to be with something like the Supplies and protection management Unit or the engine fusebox. It really needs to have a thorough diagnostic with Citroen to determine though.