Mot advice please.

[John.]

After a bit of advice regarding the wife's Renault Megan please 2014 model.
Its been parked up for about 18 months and started / moved around the drive most weeks
last week the battery seemed to be playing up so I've bought a new one as specified for the model after fitting this a warning text keeps scrolling across the dash " check stop start function "
Would this be an Mot failure with the new rules ?
I can't find any way to reset the car in the drivers hand book and don't fancy taking it to the local main dealership as they really haven't impressed us since buying the car from them.

 

[two]

I don't think so (don't know for sure) but you'd be better off selling the vehicle if you don't use it.

 

[Pausim]

On most cars I think you can turn this function on and off. Perhaps if you tried this it would reset, it may even be that having been without power it just wants to make sure you make a selection.

 

[gus-lopez]

After a bit of advice regarding the wife's Renault Megan please 2014 model.
Its been parked up for about 18 months and started / moved around the drive most weeks
last week the battery seemed to be playing up so I've bought a new one as specified for the model after fitting this a warning text keeps scrolling across the dash " check stop start function "
Would this be an Mot failure with the new rules ?
I can't find any way to reset the car in the drivers hand book and don't fancy taking it to the local main dealership as they really haven't impressed us since buying the car from them.

Most modern vehicles have a specific way that the battery must be changed or even jump started ,to prevent electrical problems. Citroën being one of the worst. I can't believe Renault would be any different.

 

[pappajohn]

I believe it has to be a warning LIGHT not text on the information panel before it's a fail.

Once the car is moving it will reset itself but as already said, it will have an on/off button somewhere.

Mine says 'stop start conditions not met' so asked the dealer as its under warranty.
"Oh, it will need a new battery as it needs to be at least 80% charged and its coming up to 3 years old so may not be charging."
It starts the car on the key, they can take a running jump.... 3 year old AGM battery showing 12.4v after 24hrs stood.

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[Deneb]

If it has Start Stop there is almost certainly a secondary battery somewhere on the vehicle and a monitoring system to regulate the Start Stop function. There will be a specific method to follow for disconnecting and replacing the main vehicle battery as the condition of both batteries is monitored by the ECU and has to be reset on battery replacement. On my Volvo the dealer would do this via diagnostic software, but it can also be achieved by leaving both positive and negative cables to the main vehicle battery disconnected for at least 6 hours before connecting the replacement battery.

The Stop Start message is probably a result of the battery monitor sensing not having been reset, but could mean that the auxiliary start stop battery has also failed. Repeatedly starting the car to only run it for a short period and or move it a short distance will be taking a lot out of your batteries and will not have been doing your engine a lot of good either.

 

[ambulancekidd]

This little video might help bolster the advice @Deneb has told you.
Sadly its a video with subtitles, but IMHO it is interesting.

 

[tonyidle]

This little video might help bolster the advice @Deneb has told you.
Sadly its a video with subtitles, but IMHO it is interesting.

The video refers to hybrid vehicles. Our Smart MHD has one battery only. I can't imagine why two would be needed for Start / Stop in a purely ICE car.

 

[pappajohn]

The video refers to hybrid vehicles. Our Smart MHD has one battery only. I can't imagine why two would be needed for Start / Stop in a purely ICE car.

Agreed, my Hyundai has one 70ah AGM battery.
I think most stop start vehicles use AGM for their slightly higher charge rate and deeper discharge.

 

[Pausim]

On a bit of a change of tack I had my motorhome MoT’d this week and thought it was useful to be given the mass and axle weights. Is this a feature of the new MoT or have I just missed it previously? I guess the weights include a driver who would be needed to apply the brakes.

Hope this is not seen as hijacking the original MoT thread.

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[Deneb]

The video refers to hybrid vehicles. Our Smart MHD has one battery only. I can't imagine why two would be needed for Start / Stop in a purely ICE car.

To share the load of the additional engine starts and running of consumers whilst the engine is stopped, that would otherwise place an additional load on the normal vehicle battery that could damage it and/or shorten its life.

My car is not a hybrid and I know of several non hybrid vehicles built by other manufacturers than Volvo which have additional support batteries when fitted with Stop Start systems.

I don't know whether the OP's Megane has an additional battery or not. I could spend time searching the internet to find out, but reason that the OP could do that just as easily. I'm sure he could also search for reasons why his Check Stop Start system message might appear, but having occurred right after replacement of the vehicle battery it is more than likely that it is related to the functional monitoring of the Start Stop system not having been reset, the car having been jump-started or a battery charger having been incorrectly connected.

 

[Geo]

On a bit of a change of tack I had my motorhome MoT’d this week and thought it was useful to be given the mass and axle weights. Is this a feature of the new MoT or have I just missed it previously? I guess the weights include a driver who would be needed to apply the brakes.

Hope this is not seen as hijacking the original MoT thread.

Pre/early Computor MoT, the tester would input the weight from an official brake test weight chart
Now fully automated weight info is set by the system, The tester just inputs actual reading, from rollers
No tester should ever rely on Customer info, His job depends on it

 

[Pausim]

No tester should ever rely on Customer info, His job depends on it

I knew I hadn’t supplied the info, which is why I found it helpful to be given it. Saves taking it to a public weighbridge. First MoT for this vehicle but I do not recall being given it on previous reports.

 

[joka250]

Hardly good technical advice but given the complexity of vehicle electronics these days my advice when disconnecting or removing a battery is park vehicle switch off and remove ignition key and have a brew. While drinking it check on internet if any special procedure for that vehicle.

 

[joka250]

On a bit of a change of tack I had my motorhome MoT’d this week and thought it was useful to be given the mass and axle weights. Is this a feature of the new MoT or have I just missed it previously? I guess the weights include a driver who would be needed to apply the brakes.

I may be wrong but surely the weights given are not specific to that vehicle at that moment. They are the manufacturers weight figures for that model. Therefore of limited value in judging overload or not.

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[Pausim]

I believe the figures I was given were taken from the MoT machinery. They certainly don’t tie up with any figures given by the manufacturer on the Certificate of Conformity.

 

[tonyidle]

To share the load of the additional engine starts and running of consumers whilst the engine is stopped, that would otherwise place an additional load on the normal vehicle battery that could damage it and/or shorten its life.

My car is not a hybrid and I know of several non hybrid vehicles built by other manufacturers than Volvo which have additional support batteries when fitted with Stop Start systems.

I don't know whether the OP's Megane has an additional battery or not. I could spend time searching the internet to find out, but reason that the OP could do that just as easily. I'm sure he could also search for reasons why his Check Stop Start system message might appear, but having occurred right after replacement of the vehicle battery it is more than likely that it is related to the functional monitoring of the Start Stop system not having been reset, the car having been jump-started or a battery charger having been incorrectly connected.

I understand why a greater capacity might be needed and why the OEM might choose to install a bigger battery or a second battery to increase capacity. What I don't understand is why battery 2 isn't replaced at the same time as battery 1. One would assume they're both the same size?

 

[Speve]

We have a Fiat Panda 4x4 with stop start and I always have it turned off as it seems to kill batteries.the strange thing is when it’s off the switch light is on can be confusing if you don’t realise it. Had to have a new battery around three years old.

 

[joka250]

I believe the figures I was given were taken from the MoT machinery. They certainly don’t tie up with any figures given by the manufacturer on the Certificate of Conformity.

My belief is that for the weights given to have any value in determining your laden weightthey have to be taken by using a calibrated weighbridge. The weight figures used in MOT are based on manufacturers figures. I can't imagine a test station having a weighbridge . The definitive answer will come from your test station.

 

[Cavs]

My belief is that for the weights given to have any value in determining your laden weightthey have to be taken by using a calibrated weighbridge. The weight figures used in MOT are based on manufacturers figures. I can't imagine a test station having a weighbridge . The definitive answer will come from your test station.

I believe the weight of each axle is measured by the rolling road in order to calculate braking efficiency. I've often used the displayed weights to note the axle weights.

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[Pausim]

My understanding is that the rollers weigh the vehicle, as reported by @Geo and @Cavs . The manufacturers figures were not the ones shown on the report.

 

[John.]

Thanks for all the advice folks
Thinking I'll just have to take it for an mot at least that way I can take it for a couple of mile run with any luck perhaps it might reset itself?

 

[Geo]

The weights used in mot brake testing have no bearing and have no other use or application
They are a vosa/dvsa formula
Not all rollers weigh the vehicle and calculation is based on more than kerb weights

 

[John.]

Well it passed the mot and the stop/start text made no difference thankfully.
Unfortunately the few miles drive didn't get it to reset so we'll give it a run into North Wales and see how that goes.

 

[DP+JAY]

My understanding is that the rollers weigh the vehicle, as reported by @Geo and @Cavs . The manufacturers figures were not the ones shown on the report.

At our last MoT the weights from the brake rollers showed ours to be 500 kg overweight. I queried this with the tester who said they are not reliable. Took it to a weighbridge & it was 300kg under. That's a difference of 800kg between brake rollers & weighbridge.

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