Battery ?

[robskiing]

Hi I've had the car for a year now it's not my primary vehicle as I use a van for my work .

What I have noticed is that I can't get rid of economy mode even after the car has been on a decent run lets say a round trip of 30 miles a mix of motorway and local .

Is this a sign that the battery is on its way out just wondering if anyone could shed some light on this.

[Randombloke]

Had a problem with this earlier this year, partially solved, the negative battery cable somewhat corroded and showing signs of Copper Sulphate, replaced cable and Eco mode is now occasional.

 

May replace positive cable too, but beware cable is massive expensive for what it is...

[andymarve]

Clean the battery terminals and the battery leads. With any luck that should solve it.

[MikeLane]

"Clean the battery terminals and the battery leads. With any luck that should solve it."

 

....and smear them with petroleum jelly (Vaseline).

[robskiing]

Hi thanks for the replies sorry if I'm gonna come across a little bit thick what's the procedure in disconnecting the battery and reconnecting just a bit worried about the cars computer cheers

[Johndouglas]

what's the procedure in disconnecting the battery and reconnecting

A search of the forum will throw up the procedure several times, but here it is to save you some time.

 

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.

 

 

Reconnect the vehicle battery, wait for half a minute (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.

You'll need to reset your clock.

[paul.h]

If you look on the internet you are likely to find lots of different procedures for battery disconnection/reconnection and depending on if you want to do a bsi reset. The one that I have used on many occasions is in the Common Problems pinned topic and copied below but the important thing seems to be to not do it too quickly so the bsi has time to shut down and start up. Also since our cars are kept on the drive the doors and windows need to be closed whilst the battery is off so I have not been able to lean through a window and do anything. So the batteries have been reconnected and then left for a few minutes, the driver's door has been opened, I have got in the car, shut the door, then waited for the bsi to shut down again before then using the key in the ignition switch as noted below. The 1 minute intervals are not exact, just any longer and it would take too long. If you do lean through a window and use the key in the ignition switch, make sure the gear lever is in neutral first.

 

16. Odd electrical problems caused by wrong battery disconnection procedure.

If you need to disconnect the battery and not do a BSI reset procedure, I have found the following has not given me any problems on a 2004 and 2007 C5 and a 2003 C3:

- remove the ignition key from the car

- open the bonnet

- wait a few minutes for the BSI to shut down

- disconnect the battery negative terminal

 

When reconnecting

- ignition key out of the car

- reconnect the battery

- wait a few minutes

- insert the key in the ignition and wait a minute

- turn the key to the first position and wait a minute

- turn the key so the dash lights come on and wait a minute

- start the engine

- take the windows down and up to reset the anti pinch

- reset the clock (and radio on the C3).