The heater fan on my 2015 C4 grand picasso only runs when the ignition/auxiliary is on. As soon as the engine is started the fan stops. There's voltage supplying the blower motor control module in both modes.
Any ideas?
C4 grand picasso 2 heater fan problem
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Paul-R
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Re: C4 grand picasso 2 heater fan problem
Welcome to the forum. The first thing I would try is a BSI reset. It costs nothing and is a starting point. viewtopic.php?p=601679#p601679
How old is the battery? Modern cars are somewhat fussy about this.
How old is the battery? Modern cars are somewhat fussy about this.
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.
Inside every old person is a young person wondering what the hell happened.
"Trying is the first step towards failure" ~ Homer J Simpson
Inside every old person is a young person wondering what the hell happened.
"Trying is the first step towards failure" ~ Homer J Simpson
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H Nancarrow
- Posts: 3
- Joined: 16 Sep 2025, 10:37
Re: C4 grand picasso 2 heater fan problem
I've just done a BSI reset and the problem is still there.
The battery is about two and a half years old and hasn't' given me any problems since it was fitted.
The battery is about two and a half years old and hasn't' given me any problems since it was fitted.
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Paul-R
- Moderating Team
- Posts: 8972
- Joined: 07 May 2009, 16:24
- x 1860
Re: C4 grand picasso 2 heater fan problem
Does the car have Stop & Start and does it work?
In many cases strange electrical problems turn out to the BSM (engine fuse box) or BCSU (battery charge status control unit) but the car needs reading for DTCs (error codes) with a high end diagnostic machine, preferably Diagbox, to narrow down the possibilities. It could still be the battery if it's been discharged a lot too many times or is the wrong type.
How long have you had this problem?
In many cases strange electrical problems turn out to the BSM (engine fuse box) or BCSU (battery charge status control unit) but the car needs reading for DTCs (error codes) with a high end diagnostic machine, preferably Diagbox, to narrow down the possibilities. It could still be the battery if it's been discharged a lot too many times or is the wrong type.
How long have you had this problem?
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.
Inside every old person is a young person wondering what the hell happened.
"Trying is the first step towards failure" ~ Homer J Simpson
Inside every old person is a young person wondering what the hell happened.
"Trying is the first step towards failure" ~ Homer J Simpson
-
H Nancarrow
- Posts: 3
- Joined: 16 Sep 2025, 10:37
Re: C4 grand picasso 2 heater fan problem
Just replaced the blower motor control module and that seems to have cured the problem. I suspect that the old unit had become sensitive to the slightly higher voltage when the alternator was running.
Thank you for all your support
Thank you for all your support