Start/Stop Issue Advise needed, Belt Tension?

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Roadrunner1
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Start/Stop Issue Advise needed, Belt Tension?

Post by Roadrunner1 »

Hi Guys,

I have an issue with my 2017 C4 Grand Picasso. My car has Start/Stop system, when I come to a stop the engine stops and goes into ECO mode (Green ECO Light on) when I lift the brake I hear a squeal then the engine doesn't restart. I have to put the car back into neutral and press the engine start button to get the engine started again. I have replaced the battery with a new one AGM one.

Do you think I need a belt or tensioner?

Any help and advice so I know what to look for would be really appreciated.

Many thanks

RR1

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GiveMeABreak
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Re: Start/Stop Issue Advise needed, Belt Tension?

Post by GiveMeABreak »

To be honest with you, you really need to have it diagnosed as there can be so many issues regarding these systems and it is impossible to diagnose remotely.

There are several technical bulletins concerning the stop and start system on these, ranging from a software update, to replacement of the central voltage retaining device to issues with the electrical harness etc., etc. That's without looking at the alternator - of which you have a reversible type - so yes, it could also be the belt that needs replacing.

Each of the resolutions will depend on the specific fault code(s) produced, so doubly important to have an accurate diagnosis. The wrong diagnosis can prove expensive on replacing unnecessary parts.

So if I were you, get it looked at by Citroen (I take it your car is just out of warranty now) as they will likely save you money in the long run if you take it to a non-specialist with little experience in these systems.

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Roadrunner1
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Re: Start/Stop Issue Advise needed, Belt Tension?

Post by Roadrunner1 »

Hi thanks. Yeah be out of warranty now.

I noticed a new noise in last couple of weeks which I thought was coming from that area. It was only after replacing the battery the Stop start now does this, is wasn’t kicking in at all with the old battery.

Many thanks.

RR1

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Paul-R
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Re: Start/Stop Issue Advise needed, Belt Tension?

Post by Paul-R »

If the stop/start uses a reversible alternator then I would think it highly likely that it's the belt and/or tensioner. Do you get any slight chirrups when switching on headlamps or heated rear window or any other high current drain device?

How many miles has the vehicle done?

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GiveMeABreak
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Re: Start/Stop Issue Advise needed, Belt Tension?

Post by GiveMeABreak »

When you replaced the battery - I assume you replaced it with exact specifications as the old one? The system needs to be told the type of battery level when replaced - but shouldn't be an issue if you have replaced it with same Level, type and capacity.

The Battery Charge Status Unit also takes at least a night of uninterrupted activity (no opening of the car doors or operation of any equipment) to calibrate after a battery change.

There are specific conditions for the Stop Start system to both stop the engine and restart it - so not restarting does look like it has attempted to restart but can't for some reason. Hence the investigation needed really. For now, you'll have to just disable the Stop / Start system each time you start the engine until such time as you can get it looked at. At least this will prevent the engine from activating the 'stopping' side for now.

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Re: Start/Stop Issue Advise needed, Belt Tension?

Post by RichardW »

On S-S systems with reversible alternator, there are 2 belt tensioners - one for normal running, and one for the reverse when the alt starts the engine. I would say it is almost certain in your case that the reverse one has failed - a few have been mentioned on here, I suspect that as they run normally unloaded, and then are suddenly called into load when starting the engine, the spring just gives up. You won't need a computer for this, just no 1 Eyeball - get the engine warmed up so that SS is active, then get your glamorous assistant to get the engine to stop, then observe the belt as clutch is pressed - if the alt spins, and the belt doesn't there is your answer.

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Roadrunner1
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Re: Start/Stop Issue Advise needed, Belt Tension?

Post by Roadrunner1 »

Hi thanks for replies.

I have noticed slight chirrups on occasion but they have always seemed random.

It’s done 37,000 miles.

Many thanks

RR1
Paul-R wrote:
01 Feb 2021, 15:09
If the stop/start uses a reversible alternator then I would think it highly likely that it's the belt and/or tensioner. Do you get any slight chirrups when switching on headlamps or heated rear window or any other high current drain device?

How many miles has the vehicle done?

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Roadrunner1
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Re: Start/Stop Issue Advise needed, Belt Tension?

Post by Roadrunner1 »

Assuming it’s this got a price for Belt + Tensioner Kit, £298 fitted main dealer.