C4 Coupé 2.0 HDI eletronic issues

[VeigaN]

Good morning, everyone!

I recently bought a 2005 C4 Coupé 2.0 HDI—a car I’ve always liked and a long-time dream of mine to own. However, I’ve been having a few issues and need your help.
I'm having symptoms like: sometimes it won't start, it's completely random, but then it starts after 1 minute, 5 minutes, or 10 seconds . I thought it might be the crankshaft sensor, but I have other associated symptoms that are also completely random: the service light turns on randomly, low beam headlights flicker, central locking doesn't always work, side mirrors don't always unfold, and the tachometer RPM display has even failed to turn on once, then flickered before staying on for good. I'm starting to think it might be the BSI.
In your experience, what could this be?
I’d appreciate any help, as I'm getting desperate since this is my daily driver.
Thank you!!

[mickthemaverick]

With that many oddities I'd suspect the battery and BSI first. Is the battery showing 12.7V when all off and 14V plus with the engine running, ie the alternator is charging. I suggest you do a BSI reset following the procedure in the link below and then measure the battery voltages and see what you find.

viewtopic.php?p=601679#p601679

[VeigaN]

EDIT:

The windshield wipers also run randomly. The central locking also doesn't always work, and the key remote control doesn't work.

[VeigaN]

With that many oddities I'd suspect the battery and BSI first. Is the battery showing 12.7V when all off and 14V plus with the engine running, ie the alternator is charging. I suggest you do a BSI reset following the procedure in the link below and then measure the battery voltages and see what you find.

viewtopic.php?p=601679#p601679

Hi!!!
Thank you for your reply.
I'll do what you told me, and then I'll tell you something.

[Paul-R]

How many kilometres has it done? How old is the battery?

[VeigaN]

How many kilometres has it done? How old is the battery?

Hi!
198k km.
The battery is new. But I'll test it later today.
The car hasn't been driven in 3 years.

[Paul-R]

Is the battery new before or after the three years?

[VeigaN]

Is the battery new before or after the three years?

2 weeks new!

[VeigaN]

With that many oddities I'd suspect the battery and BSI first. Is the battery showing 12.7V when all off and 14V plus with the engine running, ie the alternator is charging. I suggest you do a BSI reset following the procedure in the link below and then measure the battery voltages and see what you find.

viewtopic.php?p=601679#p601679

So, I just measured it now and it’s 13.10 turned off and 14.4 turned on. I think the battery and the alternator are good, apparently. I’m going to follow the steps and do a reset as indicated in the link you sent me.

EDIT: It's still the same. After a few minutes the central locking no longer works again and the mirrors don't open.

[Paul-R]

I think your next step will be to have the vehicle read for error codes (DTCs) with a high end diagnostic machine, preferably Diagbox.

[VeigaN]

I think your next step will be to have the vehicle read for error codes (DTCs) with a high end diagnostic machine, preferably Diagbox.

Thanks. I'm thinking on buying one. Until there I don't know what to do. Probably I'll to to an auto electrician.