mbradbrook 0 Posted July 6, 2007 Evening all, The battery on my VR6 has died so i'm picking up a replacement from VW tomorrow. The question is when i disconnect the old one will i have any problems with the ECU basic settings or the alarm (Sigma M30). I've gone for the VW battery so that i know the padded cover will fit it. Any help would be much appreciated. Cheers Matt Quote Share this post Link to post Share on other sites
double-6s 0 Posted July 6, 2007 I've never had any problems with settings after changing a battery mate. Just run it as normal and it'll be fine. As for the alarm, I wouldn't know as my alarm was ripped out by the last owner! Quote Share this post Link to post Share on other sites
gg7aph 0 Posted July 6, 2007 I'm interested to know the answer to this one too. I had to recently replace my battery and can't help but think my VR6 has gone a little 'flat'. According to the article in the knowledge base after performing the various actions to teach the Lambda O2 values a car requires hooking up to VAGCOM.....is this true? why is this? this last part of the knoweldge base article isn't really explained..... Quote Share this post Link to post Share on other sites
tonedef 9 Posted July 7, 2007 Sometimes after the battery has been disconnected mine feels no different, other times it feels rough but does seem to improve after driving for a while. I go through the basic setting routine anyway, it's a good excuse to go out for a drive around for half an hour :lol: Quote Share this post Link to post Share on other sites
gg7aph 0 Posted July 7, 2007 But do you do the final section that requires VAGCOM? or do you jsut do the part that states: 1) Drive from 25mph in 4th gear for at least 4 seconds with constant mid throttle (steady gentle acceleration). 2) Drive from 3,500 rpm in 3rd gear for at least 3 seconds at full throttle (hard acceleration). 3) At the end of 1) or 2), allow the Corrado to de-accelerate in the gear with the throttle closed, no brake application. 4) 1), 2) and 3) can be repeated several times. 5) At about 5 minutes, allow the engine to idle for one minute. After the initial 10 minutes, drive the car normally for a further 20 minutes minimum to allow O2 "learnt" values to be established. Idle will be complete after 10 minutes. The mid and full throttle values will take upto a further 20 minutes to establish. Quote Share this post Link to post Share on other sites
tonedef 9 Posted July 8, 2007 But do you do the final section that requires VAGCOM? or do you jsut do the part that states: Yes, every time, I do have Vagcom though so it's no problem. The write up states there's no point doing all the other stuff if you don't check the Basic Settings but the first time I read about the whole procedure in the Sprinter years ago there was no mention of this so I don't know for sure what's right. The engine definitely feels better after the first few minutes from starting though. Quote Share this post Link to post Share on other sites
gg7aph 0 Posted July 8, 2007 Sorry to be a simpleton - but what is the purpose of the VAGCOM proceedure? Just to check the basic settings are all at their correct values? Does anyone in the NE have VAGCOM I can get my hands on - seems a bit extreme to take it to the stealers for this, despite the fact I want the car in tiptop nick..... Quote Share this post Link to post Share on other sites
Jim 2 Posted July 8, 2007 You shouldn't need VAGCOM after just disconnecting the battery! As has been said, the ECU should relearn values from the car as you drive it.. so just change the battery over and take it for a good drive in a variety of situations - open road, bit of traffic and so forth so that it can relearn appropriate values. Quote Share this post Link to post Share on other sites
Roger Blassberg 0 Posted July 9, 2007 I have just changed the battery on mine and there seemed to be no adverse effect on the running, idle, mpg is as good/bad as ever, etc even without doing a basic settings. As has been said by others, it will re-learn the necessary lessons just by varied driving. Incidentally, just getting the battery out is quite a task. I ended up taking the headlight out to get e proper look at the fixing clamp bolt which was well-and-truly corroded. I finally got it out with one of those left hand thread bolt shifter sockets. And my car has aircon so there is another hose in that area to get the battery past. Ideally you need an assistant to hold the hoses out of the way whilst you get both hands on the battery. Or alternately a beginner's course in gynaecology....... Best wishes RB Quote Share this post Link to post Share on other sites
dr_mat 0 Posted July 9, 2007 There is a proper procedure for changing the battery. It involves amongst many other things, making a note of the current adapted values from the ECU before disconnecting the battery, and re-setting them afterwards. Though as pointed out, after a cold reset, the ECU goes into fast-learning mode anyway, so it should get back to pretty close to the correct figures pretty quickly. Some cars seem to require doing the basic settings stuff, others don't. I have heard of some VRs that get really rough running for weeks after an ECU reset, and I've heard the opposite too - the car runs slightly rich for a while and runs a bit sweeter than normal till it goes back to the default slightly-lean .. Quote Share this post Link to post Share on other sites
mbradbrook 0 Posted July 9, 2007 Evening all, Just an update - managed to change the battery. The clamp bolt undid easily but the battery is quite a tight fit in its mount. The most difficult bit was refitting the jacket and cables for headlight loom, aircon and amp. The alarm was no problem and the car seems to be running very well although i did take it for a 30 mile drive for fun! thanks for your replies. Cheers Matt Quote Share this post Link to post Share on other sites
