Bradders59 Posted July 15, 2023 Report Share Posted July 15, 2023 Brother in law has asked me to fit a new battery to his 987.2 on Monday. Im happy to help, but I have a vague memory of reading that the car needs to know a new battery has been fitted, otherwise it can cause problems ? Any info and advice much appreciated, thanks. Quote Link to comment Share on other sites More sharing options...
iborguk Posted July 15, 2023 Report Share Posted July 15, 2023 No coding required for a 987.1 /987.2 battery change. Quote Link to comment Share on other sites More sharing options...
Paul P Posted July 15, 2023 Report Share Posted July 15, 2023 1 minute ago, Bradders59 said: Brother in law has asked me to fit a new battery to his 987.2 on Monday. Im happy to help, but I have a vague memory of reading that the car needs to know a new battery has been fitted, otherwise it can cause problems ? Any info and advice much appreciated, thanks. 987.2 doesn't need coding, and doesn't need to have the key in the ignition to stop the alarm going off. Straight swap - you will need to teach the windows top and bottom ( open, let go, open again, hold for 5 seconds, do the same for close - both sides) - you will also likely get a scary psm failure and possibly drive off assist failure - that's normal - there is a reset procedure - but typically drive it slowly around the block and that goes away. Done it a couple of times on a my current and previous car. Quote Link to comment Share on other sites More sharing options...
iborguk Posted July 15, 2023 Report Share Posted July 15, 2023 The "how-to"... https://www.porscheclubgb.com/forum/download.axd?file=0;1066901 1 Quote Link to comment Share on other sites More sharing options...
Bradders59 Posted July 15, 2023 Author Report Share Posted July 15, 2023 Excellent. Thanks, both of you. Quote Link to comment Share on other sites More sharing options...
Bradders59 Posted July 15, 2023 Author Report Share Posted July 15, 2023 Brother in law has suggested using jump leads connected from terminals to new battery to ensure no loss of settings etc. Seems like a feasible suggestion. Any reason not to do this ? Quote Link to comment Share on other sites More sharing options...
neil.c Posted July 15, 2023 Report Share Posted July 15, 2023 I wouldn’t bother if I were you, it is only 12 Volts, but there is a lot of energy stored in a car battery if you get a short it could be spectacular. I ran the battery down in our car in the past, I got a few error codes, however a quick drive sorted them out Quote Link to comment Share on other sites More sharing options...
Paul P Posted July 16, 2023 Report Share Posted July 16, 2023 Agree with above - more risk of short circuit than any potential benefit - if you are going to do it then a "memory saver" plugged into the ciggy lighter is probably easier ( a few quid on amazon) - but you need a power source and juggling between old and new batteries and a potential 3rd source while trying ot lift a heavy thing in and out of the car at an odd angle without scratching anything makes it all the harder. Genuinely there is nothing really to lose - windows and PSM as previously stated plus, clock time, trip computer current value and gps position if you have nav - the full factory doc for what to do when you replace the battery is here: https://drive.google.com/file/d/1q8cfjlyTK-zN6hLbcqhMWq_wNuv8Gtpc/view?usp=drive_link - the "steering angle sensor" is the PSM error - fixed by driving round the block ( or by the process listed ). Otherwise, its really only ignition off - negative disconnect, positive disconnect, retaining bolt, then reverse and do the resets listed. Quote Link to comment Share on other sites More sharing options...
Kersh Posted July 17, 2023 Report Share Posted July 17, 2023 When I changed mine, I over thought it. Bought a battery save devise that connects into the OBD, but never used it. Swapped it straight out, but only had the PSM error, which was soon sorted with a trip round the block. Easiest way to change it is to put some old carpet in the boot (front), disconnect the battery, stand in the boot and lift the battery out! 1 Quote Link to comment Share on other sites More sharing options...
Bradders59 Posted July 18, 2023 Author Report Share Posted July 18, 2023 I advised all of the above, but he wanted to go the jump lead route just to be on the safe side. No skin off my nose, so we did it that way and everything was fine. The old battery was showing over 13v on my multimeter after it was removed (although the car had just been driven 25 miles), and is still over 13v this morning. I shall keep measuring voltage regularly to see what happens, but Im starting to have a slight suspicion of battery drain rather than knackered battery. We shall see. Quote Link to comment Share on other sites More sharing options...
Paul P Posted July 18, 2023 Report Share Posted July 18, 2023 I added this to the toolbox about 6 months ago. Used it a few times to remove “doubt” on this kind of thing. TOPDON Battery Tester BT50, 12V Car Battery Tester 100-2000CCA, for Battery Health Check Cranking & Charging Test, Data Review Available, Black https://amzn.eu/d/6aV64SJ It told me the battery that I had just replaced on the mrs Peugeot was indeed dead and also that the battery I took out of the Boxster when I put the car on Porsche warranty that lives on a ctek is still usable. 1 Quote Link to comment Share on other sites More sharing options...
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