For those that are using the Thundermax, I have a quick question about something I am seeing on my bike and wondered if anyone else has seen this.

2007 Road Glide
Thunder Max EFI Autotune with base map for K&N and slip-ons and have the 4.5 firmware upgrade

Symptom: The tach and speedometer basically turn off while the bike is running. This has happened twice, once while riding down the road and I looked at my speed and it said 0 and RPM 0. I pulle over, turned the bike off at the ignition, turned off the run switch counted to 5, and turned it back on and all worked fine.

2nd time the same thing happened but while I was in the garage and I just started it up to warm the bike, I was messing with the throttle a little, just seeing how the response was and it the tach and rpm went out. I checked for diagnostic codes and none were displayed.

Is this a TMAX problem or is this something like a voltage regulator or battery problem that I should check out. All readinds that i have seen on the battery look good.

 

I had this happen twice when I first got mine, both within the first week or so. Hasn't happened since and it's been on he bike for he last 2 1/2 months. Any more problems and I'd call Tmax, you might have a bad unit.

BTW, several people have posted about this here, and it seems to follow the same pattern; occurs when the unit is first installed then goes away. Understand though, overall this seems to be on a very small percentage of units.

 

I haven't seen this yet and I have ThunderMax on our (me & wife) bikes and a number of installs on clients bikes.

Same exact symptoms posted on another HD site. One speculation is that it happens in low voltage situations. Quote from other site, "I suspect it was caused by low voltage, both times I had my full heated gear on, all lights on...etc."

 

Let's follow that thought a little further. I realize that with a battery disconnect reinitializing is needed, but at what point in a low voltage situation would it also be necessary. Just trying to learn the quirks of the unit.
Ron

 

I know TMax is touchy when it comes to power levels. But I look at that low voltage speculation as draw, not battery level/condition. Obviously in his situation the battery was up enough to start the bike. I have seen TMax throw a low batt code on batteries that were perfectly good and although not completely full,tested over 11 volts and started the bike easily.

I wouldn't think you would need to reinitialize unless the battery was completely gone and needed to be replaced; which brings us back to disconnect. You don't need to pull the ECM fuse to charge the battery.

 

In my cases, the battery was not a problem. Bike was one month old, and I still have the same battery with no further problems. I can tell you one thing, if it's a problem with the Tmax, they'll replace it ASAP.

 

It could possibly be the VSS Vehicle Speed Sensor, and or the CKP Crank Position Sensor. They are magnetic and sometimes collect enough super fine metal debris that it will cause the speedometer and tach to intermittently act kind of strange. If the problem persists and the T-Max proves not to be the cause you might try removing them and wiping them off with a soft cloth.

Arcane