Car won’t start after I’ve replaced the battery

[Robskee_013]

Hey guys,

Long time lurker, first time poster.

So I’ve had my rcz for little over 4 months now.
Two days ago was the first time the car showed me the eco mode notification on the dash.

So as you’d expect it’s just the battery running low, I opted to get a new one and install it, seen as it’s not major technical service, and any self respecting petrol head would obviously take a whack at that.

So getting into the bay for the battery was an actual struggle but after half a pack of smokes, a few swear words here and there I was in.

I disconnected the battery and made sure not to let the leads just bounce around potentially causing a short

New battery in, (a Bosch 74AH) battery, basically what was already in there but just by a different manufacturer.

Closed it all up, making sure not to forget anything that had to be taken off it, and now....


Nothing, the car has power, the headlamps work, radio comes on and all, but she refuses to start, one semi loud tick (assuming the starter motor) and it goes silent.


Anyone ever had this issue ?

For what it’s worth; the only thing I could think of at this point were
- battery isn’t charged, seen as the eco alert pops up again
- the transponder doesn’t register the key anymore
(During the battery replacement of my previous car’s keyfob I dropped it and the transponder must have jumped out, the car did the same thing)

(To elaborate, my rcz had its battery replaced, not the keyfob)

Hope anyone can help me with this, it’s driving me up the wall

~ Robske

 

[DKZ5745]

So, other than a dead flat battery, (which is unlikely if everything else works) the only other thing that springs to mind is the immobiliser, which I’m not sure is part of the BSI control, but you could try a BSI reset, at least it can’t do any harm.If you want to try a BSI reset :-

Put the driver’s window down, lift the bonnet and ensure all
equipment is switched off.
Ensure all doors are closed and remove key from the
ignition.
Wait for 3 minutes, disconnect the vehicle battery and wait
15 seconds.
Reconnect the vehicle battery, wait a further 10 seconds (do
not open doors.)
Switch on the side lights through the driver's window.
Switch on the ignition and check system’s functionality.
Hold lock button on key down for 10 seconds.
remove key open & close door test central locking system
Start the engine and complete the system’s check.
Failure to follow this procedure could result in incorrect operation of many
BSI related items.

If this sorts it, don’t forget to let us know :thumbup:

 

[2retro]

I would say that is almost definitely the immobiliser activated because the battery was disconnected.

If BSI reset doesn't sort it though somebody disconnecting the front battery terminal then reconnecting it again whilst a helper turns key to start car before immobiliser kicks in should work. :thumbup:

Also FYI, Eco Mode comes on all the time, doesn't mean your battery has had it...

 

[Robskee_013]

Thanks a million guys, it worked out a miracle, sorry for the late reply, my login wouldnt take so it took me some time to figure out

So it turns out it just kept going in to that safe mode
i accidentally overloaded my system having it on the jumpstart giving it errors across (ESP, ABS, Brake systems)

but eventually it sorted it self out

again, thanks a lot

 

[Robskee_013]

Also FYI, Eco Mode comes on all the time, doesn't mean your battery has had it...

But my car did it within 30 seconds, it couldnt keep the headlights on long enough for the follow me home feature
so that sorta did tell me it was getting to that point

 

[2retro]

Also FYI, Eco Mode comes on all the time, doesn't mean your battery has had it...

But my car did it within 30 seconds, it couldnt keep the headlights on long enough for the follow me home feature
so that sorta did tell me it was getting to that point

In that case, you're probably right then! lol

 

[ionfly333]

hi im having the same issue and the above didnt work. can anyone help me pls?

 

[Thanosrcz]

Hi ionfly33, did you solve the problem with the battery? It was the bsi finally or something else? I'm asking because I have the same issue.

 

[Kash2001]

Hi guys following up on this, our battery was drained after a long while not driving it, and I think the immobilizer I think drained it.

So a local garage said the battery was dead and replaced it. Now it won't start it's likely the same issue but is there a difinitive answer as to whether the bsi reset sorted it or the terminals off and start as soon as connected?

Any help would be appreciated as the garage is looking to charge to sort this and it could take them a while...

Atb

 

[Kash2001]

Any update on further info would be great as the RCZ has been in the garage for days and it won't start with the new battery now on. Nor will it jump start with the old one I think. I'm pretty sure it's the immobilizer but how do you reset this as doing a BSI reset doesn't fix it.

Many thanks

 

[Pedro]

Ruling out any Key fob issues this info might explain your problem I have had the battery disconnected on numerous cars including my 200 for a few hours without a donor battery & normally powering them up caused no issues as most modern cars ECU's are programmed to reinitialise after a short power loss as the cars systems do not fully discharge unless the live & neutral are leads are tapped together to completely drain out all the remaining power

 

[Kash2001]

Hi thanks for the reply much appreciated. I doubt the garage would have completely discharged the system before putting on the new battery. I'm guessing only a couple of hours that the car was without a battery attached.

I've read that some batteries are incompatible with the RCZ or need coding in the computer system to be recognised.

It seems odd although it's been mentioned that the solenoid which I think sits on the battery could have failed ...

All very difficult.

Atb

 

[Verminator]

Put a new battery in your key Fob then put key in the ignition turn car on but don't try to start it press one of the buttons and hold for ten seconds this resets the immobiliser turn the key back remove from car press the buttons to lock and unlock then put back in ignition car should start.... Hope this works for you as it has with an other RCZer who's car was having similar issue

 

[Pedro]

Hi thanks for the reply much appreciated. I doubt the garage would have completely discharged the system before putting on the new battery. I'm guessing only a couple of hours that the car was without a battery attached.

I've read that some batteries are incompatible with the RCZ or need coding in the computer system to be recognised.

It seems odd although it's been mentioned that the solenoid which I think sits on the battery could have failed ...

All very difficult.

Atb

Battery control module (Shunt Fuse) on top of the battery it has been known for them to fail due to overheating or not enough or too much power or even a jump start can cause damage & also a dead battery left for too long is one major issue to cause problems

 

[Kash2001]

Hi Pedro thanks for the info, the garage are saying they're waiting on a Battery control unit why would not starting the car for 4-5 weeks cause this ? Or is it likely the switching of the battery snit jump-started perfectly before taking it to an MOT, where it refused to start after the new battery was installed...

Let's hope it's the BCU and doesn't have any other issues.

Atb

 

[Kash2001]

Hi Verminator thanks for the input, I passed this on but they say it's the BCU as above. Hopefully it'll be fixed soon and I'll update as to what it was...

Put a new battery in your key Fob then put key in the ignition turn car on but don't try to start it press one of the buttons and hold for ten seconds this resets the immobiliser turn the key back remove from car press the buttons to lock and unlock then put back in ignition car should start.... Hope this works for you as it has with an other RCZer who's car was having similar issue

 

[Kash2001]

The garage state the BCU failed and they picked one up within 2 days which was pretty good.

Picking it up today, so just waiting on the bill 🫣 but still don't understand why it started fine on a jump lead fine and after a battery change it failed.

Anyway it is what it is and hopefully it won't come back again.

Thanks for the input everyone and sorry for hijacking the thread a little.

Atb