Battery or Key starting issue?

[The black mamba]

Morning all,
Advice please, this morning the van wouldn't unlock on the key button, after a few goes it did but then the van wouldn't start, nothing not even a click but the ignition lights were on. I waited, tried the headlight main beam to see if battery was flat ish but the car in front lit up nicely, then I tried again to start the van, she fired up and of we went. Now seems fine. Recently I have thought the starter had seemed slow to turn over but I know a battery wouldn't suddenly be okay to go again. Any advice greatly appreciated. Thanks

 

[david173]

Halfords will do a free battery health check where they clip on a battery diagnostic tool. Might be worth doing if there is a Halfords is close to you, that way you can rule out the battery.

I've used it before, good service luckily battery was all healthy.

Free Battery Health Check | Halfords UK

Shop the latest at Halfords UK

www.halfords.com

 

[Pete C]

Could be a poor connection. The earth connection at the chassis is known to be a problem.

Pete

 

[The black mamba]

Thanks guys, great advice, I just have a feeling it's more than a battery as it started. Yet it wouldn't unlock on the remote key for a few goes and the battery would have to be absolutely knackered to not power that. Can the battery in the key cause this ?

 

[david173]

RENEW KEY BATTERY!

Gotta say this is the first time I've seen this message . . . . . RENEW KEY BATTERY! Thats fancy. normally my key/s get smashed to bits before the battery gets a chance to run low. Original key used daily from MY18 van so 3 years old.

www.t6forum.com

Assume this message would show on a low key battery?

 

[Salty Spuds]

Thanks guys, great advice, I just have a feeling it's more than a battery as it started. Yet it wouldn't unlock on the remote key for a few goes and the battery would have to be absolutely knackered to not power that. Can the battery in the key cause this ?

Could be a key fob issue. AFAIK, They use a rolling code so if the key fob has been pressed when out of range of the van, the van & fob get out of sync. A full cycle of lock/un-lock usually re-syncs the fob & van.

 

[Murdoch]

Moll battery?

 

[The black mamba]

Could be a key fob issue. AFAIK, They use a rolling code so if the key fob has been pressed when out of range of the van, the van & fob get out of sync. A full cycle of lock/un-lock usually re-syncs the fob & van.

Really? That would explain the central locking not working but not the van not starting unless it codes through the ignition as well perhaps.

Halfords will do a free battery health check where they clip on a battery diagnostic tool. Might be worth doing if there is a Halfords is close to you, that way you can rule out the battery.

I've used it before, good service luckily battery was all healthy.

Free Battery Health Check | Halfords UK

Shop the latest at Halfords UK

www.halfords.com

Thanks David

 

[Salty Spuds]

Really? That would explain the central locking not working but not the van not starting unless it codes through the ignition as well perhaps.

As I understand it (and I may be talking a load of bollox) each time you use the fob, the fob & van essentially agree which code they will use the next time they meet, this is the “rolling” part, they use a different handshake each time. This is to prevent criminals from “grabbing” the fob code when you lock the van & walk away. So if you press the fob when it’s out of range of the van, the next time you try & unlock the van, the fob sends the next code in the “rolling list”, the van isn’t expecting this code, it’s expecting the one that got used when you were out of range. That’s when they need to re-sync.

 

[The black mamba]

As I understand it (and I may be talking a load of bollox) each time you use the fob, the fob & van essentially agree which code they will use the next time they meet, this is the “rolling” part, they use a different handshake each time. This is to prevent criminals from “grabbing” the fob code when you lock the van & walk away. So if you press the fob when it’s out of range of the van, the next time you try & unlock the van, the fob sends the next code in the “rolling list”, the van isn’t expecting this code, it’s expecting the one that got used when you were out of range. That’s when they need to re-sync.

Even if that's not true it's bloody good .
Great info cheers

 

[Lightrofit]

As I understand it (and I may be talking a load of bollox) each time you use the fob, the fob & van essentially agree which code they will use the next time they meet, this is the “rolling” part, they use a different handshake each time. This is to prevent criminals from “grabbing” the fob code when you lock the van & walk away. So if you press the fob when it’s out of range of the van, the next time you try & unlock the van, the fob sends the next code in the “rolling list”, the van isn’t expecting this code, it’s expecting the one that got used when you were out of range. That’s when they need to re-sync.

That’s pretty close.

The vehicle will have a “batch” of codes that will match what the key will send, the key transmits the data, the vehicle then checks the batch and confirms it’s an authentic key.

When the key send over a data, that data is deleted from the “authorised” list.

This is totally independent of the start authorisation, which is done via RFID so no battery needed in the key to actually start the van.

Ideally you need a fault code scan using decent Diag equipment to see what faults are stored to start building a picture of what happened.