Disconnecting Battery

[Hilux2400]

996 C2 2003

 

I want to do some work on the underside of the seats and know that the electrical under-seat connector remains live even when the ignition is turned off. There is therefore a danger of activating the airbag if the connector is separated. 

 

I know that from Loren's article on door card removal that it is recommended that the -ve battery terminal is disconnected and covered first and a delay time given of at least a minute before doing any work near air bags connectors.  On my car, if I disconnect the battery the alarm goes off.  So the questions are:

 

Should I leave the ignition key in when disconnecting the battery to prevent the alarm going off?  

 

Should the ignition key then remain in when doing the work on the seat and separating the connector?

 

Will I have to go through the "idle butterfly valve reset procedure" after re-connecting the battery? 

 

Thanks for reading and it's a great web-site.

 

[RFM]

For ROW cars, the key must be placed in the ignition switch, in the "ignition on possition", and let it stand until the battery is reconected. This will prevent the alarm from being activated.

[Hilux2400]

6 hours ago, RFM said:

For ROW cars, the key must be placed in the ignition switch, in the "ignition on possition", and let it stand until the battery is reconected. This will prevent the alarm from being activated.

Thanks for the information as the alarm goes off with the key in, but with the ignition off when the -ve terminal connector is taken off.  I would have thought there would have been guidance in the handbook on this topic  for changing the battery, but nothing is given.  It's just seems strange to leave the ignition on, when disconnecting the battery.  I didn't want to try the "on" option without confirmation.

 

When the battery is re-connected will I have to do the throttle body re-set?

 

What is the time delay between disconnecting the battery and safely doing work on any air bag connections and should I make sure there is no residual power in the circuits by placing a load across the disconnected terminals?  

 

[Loren]

Yes, throttle, windows, sun rood will all need re-training.

The DME will re-train also but it will do that automatically in the first 5 miles or so.

[creekman]

Don't know about all your questions, but I do know that you'll have to reset the airbag fault once your seat is re-connected.  

[RFM]

2 hours ago, Hilux2400 said:

Thanks for the information as the alarm goes off with the key in, but with the ignition off when the -ve terminal connector is taken off.  I would have thought there would have been guidance in the handbook on this topic  for changing the battery, but nothing is given.  It's just seems strange to leave the ignition on, when disconnecting the battery.  I didn't want to try the "on" option without confirmation.

 

When the battery is re-connected will I have to do the throttle body re-set?

 

What is the time delay between disconnecting the battery and safely doing work on any air bag connections and should I make sure there is no residual power in the circuits by placing a load across the disconnected terminals?  

 

Believe me, that's the way to go for ROW cars. After disconnecting the battery, you should wait a few minutes (5 a10) to be sure. Succes.

[DBJoe996]

A general rule of thumb is to wait at least 15 minutes after disconnecting the battery to do any work on an airbag.  They have capacitors that store voltage in the case that somehow the electrical system is disrupted but the airbags may still need to be deployed.  Think crashing.  I usually wait for 30 minutes to error on the side of safety.  BTW, disconnect your alarm horn and you won't have that problem.  Also, as stated, once you are finished you will have to re-train everything.  Also, make sure you have your radio code, if necessary, prior to disconnecting the battery.

Edited August 8, 2017 by DBJoe996

[Richard Hamilton]

As far as removing the seat is concerned, you won't have any airbag problems with a UK 996.  The seat buckles are not connected to the airbag control unit like they are on a US 996.

Edit: Also, before disconnecting the battery, you can switch the ignition on, and then switch it off again, but you must leave the key in the ignition.  The alarm siren is signalled by the loss of the Terminal 86S supply, and this supply remains on until you remove the key.

Edited August 8, 2017 by Richard Hamilton

[wyovino]

Interesting.  I replaced my battery last year and was surprised that I didn't have to reset anything.  Not even the radio.  I wonder if there is a small amount of reserved storage in the system somewhere.  When I disconnected the battery to replace my door lock mechanism, I think I did have to reset the radio but nothing else.  The battery was disconnected for a much longer time.

Edited August 13, 2017 by wyovino

[Loren]

7 minutes ago, wyovino said:

Interesting.  I replaced my battery last year and was surprised that I didn't have to reset anything.  Not even the radio.  I wonder if there is a small amount of reserved storage in the system somewhere.  When I disconnected the battery to replace my door lock mechanism, I think I did have to reset the radio but nothing else.  The battery was disconnected for a much longer time.

 

US/Canada cars have a different alarm system.