Time for a new battery
04-22-2018, 10:00 PM
#1
Instructor
Thread Starter
Time for a new battery
Well it looks like my battery is just about dead. Won’t hold a charge if left to sit for a few days.
Any special steps to take before pulling the power? Will the computer need to be rebooted or anything like that or do I just pull the old one and drop in the new one?
Any special steps to take before pulling the power? Will the computer need to be rebooted or anything like that or do I just pull the old one and drop in the new one?
04-23-2018, 12:14 AM
#2
Three Wheelin'
You may (will) get a bunch of error codes if you disconect the ECU from its power source. A trickle charger may work if you have one (plugged into the cig. lighter). If you do a search you will find lots of tips an suggestions from people who have changed their battery - I’d start you off but I’m a bit pressed fro time (I DVRed Liege-Bastogne-Liege (bicycle race) and want to get to it). Anyway, this topic has been discussed before so you’ll have a lot of input. I just got a new battery last week. I had my Indy do it as I have a separated shoulder. Even with the car hooked up to a trickle charger it threw a bunch of codes he had to clear with his Durametric.
04-23-2018, 08:55 AM
#3
RL Community Team
Rennlist Member
Rennlist Member
None of the codes that show up from replacing the battery need to be cleared. They'll go away on their own within the first couple mikes of driving.
You'll get a PSM failure that will clear itself, but that's pretty much it. Disconnecting the battery will also reset the fuel trims so it nay seem like the car us running a little funny when you first start it, but that will smooth out quickly as well.
Don't latch the frunk with the battery disconnected - put a T-shirt / rag over the latch receiver to avoid doing it out of habit.
You'll get a PSM failure that will clear itself, but that's pretty much it. Disconnecting the battery will also reset the fuel trims so it nay seem like the car us running a little funny when you first start it, but that will smooth out quickly as well.
Don't latch the frunk with the battery disconnected - put a T-shirt / rag over the latch receiver to avoid doing it out of habit.
04-23-2018, 11:02 AM
#4
Replacing the battery will actually clear all codes. You may need to drive for about 1000 feet to clear the PASM error and re-set the windows . Do not plan to get your car inspected for emissions for a few days or it will fail as the ECU will not indicate readiness. Driving in all types of situations will repopulate the data in the ECU. Again, this generally takes a few days of driving under various conditions.
04-23-2018, 01:03 PM
#5
Rennlist Member
None of the codes that show up from replacing the battery need to be cleared. They'll go away on their own within the first couple mikes of driving.
You'll get a PSM failure that will clear itself, but that's pretty much it. Disconnecting the battery will also reset the fuel trims so it nay seem like the car us running a little funny when you first start it, but that will smooth out quickly as well.
Don't latch the frunk with the battery disconnected - put a T-shirt / rag over the latch receiver to avoid doing it out of habit.
You'll get a PSM failure that will clear itself, but that's pretty much it. Disconnecting the battery will also reset the fuel trims so it nay seem like the car us running a little funny when you first start it, but that will smooth out quickly as well.
Don't latch the frunk with the battery disconnected - put a T-shirt / rag over the latch receiver to avoid doing it out of habit.
Meh, cleared it and all is well...
04-23-2018, 01:06 PM
#6
+1 to that ^. I have an iCarsoft POR-II so I cleared the codes with that, and did the manual window reset, but good to know they would have cleared themselves though! I now have a tender with a supply setting (CTEK MUS 7002) which keeps enough juice flowing to preserve settings. The hardest part for me was physically exchanging the battery, as I'm not very tall, and the battery is heavy. Fortunately I'm not very big so I stood in the frunk and had a helper to hand off the old and new batteries.
04-23-2018, 01:08 PM
#7
RL Community Team
Rennlist Member
Rennlist Member
You can if you DON'T change the battery and try to start it with a dead one. I did this the other day it threw an airbag light, which is obviously a permanent code. Learned (googled) it and determined it is a common problem with low/dead batteries on P-cars.
Meh, cleared it and all is well...
Meh, cleared it and all is well...
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04-23-2018, 01:29 PM
#8
Rennlist Member
Just to share what I learned with the group, as I am somewhat skilled in auto coding on other makes (BMW/Volkswagen/Audi, etc.)
Even 997.2's computers aren't as complex as a modern Volkswagen's. They don't permanently mark lights and such "offline" when they get a high voltage spike (ya, I just happen to do that to too). They also don''t have a battery charge level "learn/recode" setting, like in a BMW with an AGM battery.
In general, they don't have huge sensitivity to the battery charge level. That is, with the exception to throwing an airbag light if they get really really low and one tries to start them. Even then, it is clear-able and you are on your way.
Even 997.2's computers aren't as complex as a modern Volkswagen's. They don't permanently mark lights and such "offline" when they get a high voltage spike (ya, I just happen to do that to too). They also don''t have a battery charge level "learn/recode" setting, like in a BMW with an AGM battery.
In general, they don't have huge sensitivity to the battery charge level. That is, with the exception to throwing an airbag light if they get really really low and one tries to start them. Even then, it is clear-able and you are on your way.