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NEW BATTERY - DO I NEED TO RESET COMPUTER?

arneycl

New Member
Joined
Aug 28, 2010
Messages
6
Location
Odon, Indiana
Hi guys. First, let me say that I've tried searching this topic but for some reason the search feature isn't working for me. So I appologize if this is on the forum already.

I just put a new battery into my 2005 Avalanche. Do I need to reset the ECU or whatever you call it? If so, how is it done? Can someone point me to the directions on how to do it?

Also, I know there are alot of topics about MPG but I used to get 18 MPG but for the past year and half I've only been getting 16. My Avalanche is a 2005 and it has 75,000 miles on it. I've not changed the spark plugs/wires. Any suggestions for improving would be great. My driving habits have not changed so it has me puzzled why the MPG has decreased so much.

Thanks everyone.
 
When you disconnect the battery the computer will reset automatically.
Tune up is recommended at 100K but it couldn't hurt doinhg it at 75K. Have you cleaned your Mass Air Flow (MAF) sensor, changed your air filter, added som fuel injector cleaner or seafoam to the gas. These will all help with the gas mileage. And make sure the tire pressure is adequate. Have you changed the brand of gas you have been using?
 
It doesn't have to be disconnected for any certain amount of time?

I haven't cleaned the MAF Sensor. I had never heard of doing that until today. I don't even know where it is located. Pic or good description would be great. What do you clean it with?

I have a new air filter and I have added Seafoam to the gas.

Haven't changed the brand of gas.

I also have new tires.
 
If the battery was disconnected for 10 minutes it should reset the computer.
You can read about cleaning the MAF in this thread:
http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,92317.msg1868122.html#msg1868122

It will show you where it is and what to use to clean it. Just read through the entire thread  (y)
 
Chevrolet Avalanche Maintenance & Care; Chevrolet Avalanche Problems, Questions & Answers; Start here and if you can't find specifics what you are looking for there or search ask for guidance like you have. As you can see you can't find better people to get help from then the members at CAFC.   
This my first computerized and injected vehicle with CAFC I have saved a lot of money not having to use a shop. 
My :welcome: to the club.
look out for the  >:D mod virus
JV
 
One thing that could be causing your drop in mileage might be your brand of gas changed most gas changed to 10% ethanol in the past 1-3 years (depending on were you live) and that can cost you 1-3mpg. If your vehicle is flex-fuel capable it seems to be toward 3mpg because it switches partway to the E85 tune.
 
arneycl said:
Hi guys. First, let me say that I've tried searching this topic but for some reason the search feature isn't working for me. So I appologize if this is on the forum already.

I just put a new battery into my 2005 Avalanche. Do I need to reset the ECU or whatever you call it? If so, how is it done? Can someone point me to the directions on how to do it?

Also, I know there are alot of topics about MPG but I used to get 18 MPG but for the past year and half I've only been getting 16. My Avalanche is a 2005 and it has 75,000 miles on it. I've not changed the spark plugs/wires. Any suggestions for improving would be great. My driving habits have not changed so it has me puzzled why the MPG has decreased so much.

Thanks everyone.

You don't need to worry about resetting the ECU when you change the battery. Unless you had a code in the computer or an engine light on it's not necessary.
 
Thanks everyone for the info. I will clean the MAF as soon as I can and I will report back on if my MPG has increased. Might be a little difficult though during the Winter time as my wife wants the vehicle warmed up so that sucks the gas.
 
I think 16 mpg is good- 18 is great. Clean the MAF and use Chevron Techron injector cleaner in a couple taks of gas too.

Avalon
 
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