Merc Smart Tow Issue
 

Took our new boat out for her maiden voyage today. Had a BLAST (with 43 degree water... dry suits DO come in handy).,,

Had an issue with our Smart Tow. Set it on GPS mode (not paddle wheel), speed control (not RPM), launch setting at 4 and speed set at 19mph. Cruise would engage, but fluctuated between 24 and 12 mph. No wind, and water was like glass We tried varying the settings multiple times... but experienced the same results every pass... major speed fluctuation.

Any ideas?

Did you try on paddle wheel mode and get same result?

Sure did... and same result.

I apologize, I am not familiar with this specific system. I am assuming the engine is a throttle by wire( ecm controlled throttle)?

The first thing you need to check is whether you kept the key in the "on" position. I have an 08 Epic with the system and we've never had a problem, until whoever is driving is used to perfect pass and turns the key "off" to kill the motor instead of using the button on the handle. While it will turn of the motor, it also kills the power to the GPS so when you turn it back on it has to re-aquire the signal which takes a few seconds. If you take off before it does this the boat doesn't know how fast it's really going and you'll get some weird results. Hope this helps, and you'll love SmartTow when you get it figured out, easiest system ever to teach someone to drive and pull.

try it in RPM mode... If it still fluctuates, then it's an issue with the connection to the throttle body/linkage. If it's steady on RPM mode, then it's likely an issue with sensing the speed. That will at least let you know where to focus your efforts.

Both of the above suggestions are right on. But since it was the maiden voyage you should run it at different ballast and speed settings on manual first. Run it empty ballast at a slow, med, then higher speed. then repeat at medium ballast, then repeat at loaded ballast and loaded up. Once you've done that switch the smart tow on and it should be ok. The computer has to build an acceptable rpm to mph range table. It controls the engine by rpm but offers a reference for the driver in mph thru the gps...it's a great system. You only have to do the manual varying settings once, then the computer's got it.
Second the suggestion on using the green/red on/off button on the throttle, it keeps the gps from having to "re-boot" every time you turn the key on and off.
Good luck.

Hey John sorry to hear of your troubles with the smart tow. First thing is to be sure and turn your key on in the morning and leave it on the rest of the day. Everytime you shut the ignition switch to the off position it takes a few minutes for the GPS system to reload itself. There are also some settings inside the system that can tighten up the tolerances. Our tech guy will do some research and I'll let you know ASAP. Glad to see you bearing the cold and breking in that new ride. Don't forget like Greg S said be sure to vary the throttle settings during the break in period.

Haven't been online in a couple days. Thanks so much guys for the insights. Headed out again this weekend so we'll try altering ballast and speed and see if that helps!

So I've had the boat out several times now. Cruise works well at surf speed as it maintains within .2 mph... but anything above 15mph, the speed surges as much as 6mph. I've tried all different settings on the "speed filter" with no change. Dealer suggested resetting to factory default which I'll try this weekend.

Any ideas?

whats your launch control on? for both surf speed and wake speed?

Most recently launch control surf speed = 2, and launch control wakeboard speed = 4. Tried several different options with the same result... major fluctuation at wakeboard speed. Boat had a 17 pitch prop from the factory, and dealer changed out to a 16 pitch thinking that might help. WAY better hole shot... but no difference with cruise.

I'm baffled...

John

Were you able to fix your speed holding issue?

I recently changed my prop and I'm now have this issue.

Thanks

ST

Issue still not fixed. Merc/dealer have upgraded the gauge to V6.1. Have tried to re-calibrate the "PCM" (sp?)... no luck. Dealer ordered a "new/different" program to re-calibrate the "PCM" himself, but has not completed that.

Holds speed GREAT in RPM mode... holds very well in speed mode at surf speed... but at wakeboard speeds, 4-6mph fluctuation/surging. Haven't complained too loud as we've been surfing virtually all summer. But come fall and "warranty work" time, I'm gonna push 'em HARD...

Hi guys,

Got the speed holding issue fixed in 10 minutes...

This is what I did.

1) Did a master reset (see the Smartcraft manual)
2) Went in Cal1 and Cal2 setting to configure the gauges, sensors (GPS for speed, etc.)
3) Load the boat (full ballast, peoples, etc) I think that more weight while doing the calibration results in better speed holding at normal riding weight.
4) Set the Smart Tow in Speed Mode
5) Set the speed to 10 Mph
6) Set the Launch to the Launch setting you normally use
7) Launch and wait till it reaches 10 mph and it is hold steady
8) wait 20 sec
9) Increase the speed by 1 Mph
10) Wait till it reaches the new speed and it is hold steady
11) wait 20 sec
12) Do this till you reach a few Mph past your usual riding speed.
13) You are done!

Now weight the boat like you normally do and it should launch super smooth and hold it speed perfectly.

PCM is re-programmed, and I cycled thru the speeds as suggested. Works PERFECT!