I've had the Thundermax w/AutoTune on my '08 Softail Custom for about 1-1/2 months. On three occurances, my check engine light has come on. Two of the times were while I was at the Fall Rally in Myrtle Beach, and the other time was just this past weekend during a Toys For Tots ride. The first time it happened, I was pulling into the parking lot at the Harley dealer in Myrtle. I went right inside and talked to the service guys. They checked the code and told me it was just a communication problem and that there was no real issue. It did it again later in the day as I was pulling into another parking lot. This last time, I was pulling in the parking lot at our local dealer after the Toys For Tots ride. All three times I was in stop-and-go traffic. After the bike is parked for a little while and it cools down, the check engine light goes off. So my guess is that the bike is overheating. I never had that problem while the bike had the stock ecm. But maybe I was never in stop-and-go traffic while the bike was stock either. I can't remember. Is anyone else having similar issues with the Thundermax or even with the stock ecm? I'm planning on sending Zippers an email asking them what the problem is.

 

Try just unhooking the battery to clear the codes and see if it reoccurs.

 

The tech in Myrtle cleared the code after the first time it happened.

 

I see you have an air cleaner. Are you running a tuner? SERT, V&H Fuel Pak or Dynojet Power Commander?

Have you had bike dyno'd and your tuner remapped for your mods?

 

READ THE MANUAL. It tells you quite clearly that when the check engine light comes on your head temperature has reached a point of danger. It's default setting is usually in the 320 degree range.

 

The Thundermax w/AutoTune is the fuel management system. It replaces the stock ecm and O2 sensors, rather than tricking or piggy-backing off the stock ecm like some of the other fuel management systems. The Thundermax doesn't need to be dyno'd because it "learns" your bike and tunes itself.

 

Are you referring to the manual that came with the bike, or the stuff that came with the Thundermax? I didn't have this problem while the bike was stock, so would it be a problem related to the Thundermax? What would cause my bike to start overheating all of a sudden? I have a high flow air-cleaner and changed the exhaust. I would think those mods would allow the bike to run cooler. I did not ride the bike with the Check Engine light on. I saw it come one once I was in the parking lot all three times. The bike was shut down very quickly after seeing the light was on. I know a Check Engine light will come up if the bike is starting to overheat. I guess what I'm really trying to find out is if anyone else if having the same issue with their bike after installing the Thundermax. This has me kinda nervous since the Thundermax voids the motor warranty, so if my motor messes up, I'm screwed.

 

Then I would get rid of it immediately and get a SERT, Power commander or Fuel Pak.

 

I just called Thundermax tech support. The guy was very helpful. He told me that was a feature built into the Thundermax to let the rider know the bike is overheating (temp reaching 350*). He said a stock ecm will not do that. He said a stock ecm will "let you just sit there and melt" without telling you. I figured the problem was heat related since it has only done it in stop-and-go situations (bike week twice and toy run once). Luckily, the light has only come on as I'm pulling into a parking lot and I'm able to shut it down quickly.

 

WOW!! Is that true???Does installing a Thundermax void the warrenty? I've got an extended 5 yr warrenty w/ 4 years left on it. The last thing I want to do is mess with the extra coverage you pay dearly for. So...if this is true what are you guys recommending. I'm wanting to do a stage one upgrade and was looking HARD at the T'Max. Sorry to hear about your overheating problems, I thought one of the reasons for doing the stage one was to help with the cooling. Why didn't that happen in your case? I have a temp gauge in my oil dip stick and mine usually runs around 210-230, every now and then it will hit 250... 300 plus seems awful hot. I wish you the best and keep us posted. I was at bike week also...that stop and go can really get'em hot. By the way...Nice looking bike you have there.