How to restrict DF40A performance with an electronic signal

[Moonlighter]

QUESTIONS... answers added after the questions.

1. Is there a neutral switch on the engine as well as in the remote control?

Yes. They do different things. The one in the binnacle prevents the engine being started in neutral. The one on the engine prevents it being revved excessively in neutral but doesnt prevent it being started.

2. Will not resetting the oil change alarm, trigger the cut back to 3000 rpm? I have done all my own maintenance and did not know about the reset procedure. Should this set a code?
Last year i did put a oil pressure gauge in place of the Oil pressure switch and i had good pressure at idle. I dont think i read the pressure at 5200 rpm.

No, not resetting the oil change reminder wont trigger anything other than an annoying beeping.
The reset procedure is as follows, as per your owners manual:

Suzuki oil change reminders

Turn key off

Take off safety lanyard clip

Turn key on (beep)

Pull out safety button 3 times in short succession.

System beeps to show successful reset. The clip can then be reconnected.

3. The dealer recently gave me a laminated card with the reset code for the remote. I was told the engine would beep after doing the reset procedure. Mine did not beep. can anyone test there engine to see if theirs beeps every time even if you reset it three times in a minute. I have not bussed around after the reset.

If you dont get the confirmation beep, it may be due to either the reset not being done right or the “dead man” switch where you clip the lead on is not working. You can test this by starting the motor then pulling the dead man clip off, the engine will stop if the switch there is working.

4. I believe some larger suzuki outboards have two neutral safety switches. One on the motor and one in the controller. If i am cruising along at 5200 rpms and 17 mph and the neutral switch were to open up, would the computer limit the engine to 3000 rpm and if so would it throw a code?

See answer to Q1. I dont know what would happen but I strongly suspect it would instantly limit revs to 3000rpm. Never heard of it actually happening though. No fault is generated by the NTS so no code would be stored.

5. Is there a neutral switch adjustment on the controller? Or is the switch just a replacement item? Is this tricky to take apart.

NTS on engine is not difficult to replace nor expensive. Go to the “buy Suzuki Parts” link in the blue bar at the top of this page, click there, select your engine hp and year and then look thru the various pages and find the sensor and it has an expanded diagram that shows its location, to help you see how to replace it.

here is the controller i have....
https://www.crowleymarine.com/suzuki...25at-p03?ref=7


So did i
A....chase an issue for two years when a simple oil reminder reset would have solved it? No. Nothing to do with the oil reset.

B....Or is it a loose neutral switch in the controller that is now giving me two symptoms? C....Or is it really my hi pressure fuel pump? The failure to start but then starts after the throttle is jiggled is usually due to a gear linkage adjustment being out of whack at the engine end. A decent Suzuki mechanic would sort this in 5 minutes.


D.... none of the above.

You’ve likely got 2 things going on. One is the linkages being incorrectly adjusted and although the switch that prevents the engine being started is in the throttle binnacle, the adjustment to fix it is typically done at the engine end of the cables. As mentioned a good Suzuki mechanic will diagnose and fix this in a few minutes.

The other - being the engine losing revs suddenly at cruise speed, is something else. Possibly contamination in the VST that blocks fuel temporarily, then when the engine is stopped, it falls back and allows fuel thru again. Rinse and repeat. The solution is to pull VST off, open it up, clean it out. Need to know what you’re doing or get it done by Suzuki mechanic.

Could also be dirty fuel filters. Have they all been changed? Starting with the water separating filter between the tank and engine, and then all the engine mounted filters?

Could also be fuel pressure, get the pressure checked.

[timf1981]

The neutral switch is a simple momentary switch, its is either on or off. When the gear linkages move, the switch changes from on to off. Or off to on. Whatever.

We occasionally see members come on here and say that they start their engine but when put into gear, the engine wont rev past 3000rpm, and the usual cause is that the switch is loose or broken. The ecu doesn’t see the signal to tell it the engine is now in gear. So it wont let the engine rev past 3000rpm.

if the poster messes with the neutral switch. Will the engine then be able to start in forward or reverse? This would be a safety issue for his customers.

Moonlighter, you have attempted to help me with my two year old problem of motor running fine then dropping to 3000 rpm. turn off and restart and everything is fine for a while. I just posted an update after a no crank issue being temporarily fixed by moving the gear selector back and forth. So it sounds like my neutral switch was the problem all along.

here is my complete update.

2017 DF25ATL2 with remote control

2 years ago, every once in a while i would be driving along in my 16.5ft Alumicraft Escape . And the rpms would cut back to 3000 rpms.
The engine would run just fine like this but would not go over 3000 rpms when it had been cruising along at 5200 rpms.
The first time it happened i was on a large lake in Northern Minnesota. At the time i didnt dare turn it off for fear of not starting.
I made it to camp . After turning off the engine and restarting it ran fine. Even at 5200 rpms.
So i went back and set up camp. Later that day i went out fishing. After hitting a couple of spots close by i decided to head to the next bay. I was cruising at 5200 rpms when again the motor just cut back to 3000 rpms. If i shut the motor off and restarted it would idle good, and might get back up to 5200 rpms for a while then just cut back to 3000 rpm , still running just fine.

I limped around like this for three days. Sometimes cruising at 5200 rpms for long distances then it would start acting up.
When i got home i put my ebay suzuki scanner on it and had no codes. BPR scanner i believe.
While up at the lake despite having fresh gas for the trip. i flushed new gas thru the system and cleaned both filters. No change. After getting back home to Minneapolis i flushed it again.
Went out on the lake to watch some fireworks. It cut back three times before getting a quarter mile.
The next time out a buzzed around our lake for an hour. , It ran fine at 5200 rpm.
The boat was used little if any the rest of the year. The next year i took it out on a nearby lake and buzzed around for an hour with no issues. the next week took it back up north. It ran fine the first day but the second day it ran good for ten minutes then cut back to 3000 rpm. No codes, no buzzing that i can recall. I dont remember checking the three lights on the engine. I know, my bad

A new symptom popped up recently. Occasionally i get no crank when i turn the key. I can always get it started by shifting it out of neutral and back in, and it will start.

QUESTIONS...
1. Is there a neutral switch on the engine as well as in the remote control?
2. Will not resetting the oil change alarm, trigger the cut back to 3000 rpm? I have done all my own maintenance and did not know about the reset procedure. Should this set a code?
Last year i did put a oil pressure gauge in place of the Oil pressure switch and i had good pressure at idle. I dont think i read the pressure at 5200 rpm.

3. The dealer recently gave me a laminated card with the reset code for the remote. I was told the engine would beep after doing the reset procedure. Mine did not beep. can anyone test there engine to see if theirs beeps every time even if you reset it three times in a minute. I have not bussed around after the reset.

4. I believe some larger suzuki outboards have two neutral safety switches. One on the motor and one in the controller. If i am cruising along at 5200 rpms and 17 mph and the neutral switch were to open up, would the computer limit the engine to 3000 rpm and if so would it throw a code?

5. Is there a neutral switch adjustment on the controller? Or is the switch just a replacement item? Is this tricky to take apart

here is the controller i have....
https://www.crowleymarine.com/suzuki...25at-p03?ref=7

6 The outfitter i sleep at before putting in in the morning has the same motor as I do, I am not sure if the year is the same. He had his high pressure fuel pump replaced. But i dont think we had quite the same symptoms.


So did i
A....chase an issue for two years when a simple oil reminder reset would have solved it?
B....Or is it a loose neutral switch in the controller that is now giving me two symptoms? C....Or is it really my hi pressure fuel pump?
D.... none of the above?

Here is the updated fuel pump part number for my engine.
15200-94L11 and have found it at these 6 locations. Are there any sellers here you would stay away from?

Browns point $376
Precision marine $345
Boat.net $367
PartsVu $342
PPT performance product technologies $338
Marine parts source $334

What other information would you like?

[Murray]

https://www.suzukioutboardforum.com/...ki-owner-df40a

The above link won’t help you with wake in the no wake zone but you may be able to “detune” the engine to reduce overall speed?

[Moonlighter]

Now that you’ve mentioned the 4 knot limit, the neutral switch isnt going to be the solution - 3000rpm will be way too fast.

Maybe another option might be to have an annoying buzzer going off whenever the boat exceeds 4 knots in the canals? That will get the attention of the driver!

[Solarman]

If you can communicate to turn a relay on/off, then you just need to interrupt the neutral switch wire on the motor to limit the motor to 3000 rpms, not sure what speed that will be on your boats, but it's like a high idle in any gear position. With the GPS function, it might be possible to set it up automatically for certain travel areas? Outside of those certain GPS areas the relay could be turned off allowing the motor to run normally? Though you might need a secondary relay/switch to prevent full throttle (unless the throttle is lowered) when the GPS turns off. Or, maybe a relay that operates a solenoid (added) to block the throttle from going only so far in those GPS areas? Might add a flashing light to same relay to indicate "slow speed zone"?

Good luck with all that.

[benmbh]

Can you govern it so it won't go to full throttle?

We already have that, they're limited as per legal regulations for hire boats in Australia, maximum of 10 knts with 1 x 80kg adult aboard.

To get this to work at the least you are going to need to have a internet data connection set up on the boat and then a secure access so you can use something similar to the remote immobiliser to, for example, somehow turn that neutral switch off - which will then limit the engine to 3000rpm. Going to take some doing, all of that….

We already have all this setup, we have GPS aboard connected to the internet with a sim card. We can communicate with the device and control a relay on and off etc. The last piece is what to control on the engine.

Its a lot of trouble to go to to solve - what problem?? How big a problem? How often? What are the consequences?

Anything above 4 knts speed over ground creates a lot of wash with some vessels, especially when going against the tide.
It's the number one cause of complaints for our business from canal residents, there is no inherent risk other than it creates a very negative image of our business and the complaints are pretty much endless. We've tried to control this in many other ways, bonds, education, warnings, signage, blacklists etc but it doesn't help, some people just don't care about the rules.

[Moonlighter]

My main concern is I don't want to isolate the engine entirely and put the customer into a dangerous situation, these are boats out on the water. Hence why i'd only like to reduce power. If I cut the circuit to the neutral switch while it's running will the engine simply cut out?

The neutral switch is a simple momentary switch, its is either on or off. When the gear linkages move, the switch changes from on to off. Or off to on. Whatever.

We occasionally see members come on here and say that they start their engine but when put into gear, the engine wont rev past 3000rpm, and the usual cause is that the switch is loose or broken. The ecu doesn’t see the signal to tell it the engine is now in gear. So it wont let the engine rev past 3000rpm.

To get this to work at the least you are going to need to have a internet data connection set up on the boat and then a secure access so you can use something similar to the remote immobiliser to, for example, somehow turn that neutral switch off - which will then limit the engine to 3000rpm. Going to take some doing, all of that….

Its a lot of trouble to go to to solve - what problem?? How big a problem? How often? What are the consequences?

May be time to start back at the beginning and do a proper risk assessment?

Risk = likelihood x consequences. Then consider the options for mitigation strategies. The solution being considered now may turn out to be overkill for the risk involved.

[cprice11]

Can you govern it so it won't go to full throttle?

[Solarman]

I would think, if you interrupt the neural switch on the motor, making it believe it is in neutral, then it should limit the motor to 3000 rpms in any position F-N-R?

[benmbh]

My main concern is I don't want to isolate the engine entirely and put the customer into a dangerous situation, these are boats out on the water. Hence why i'd only like to reduce power. If I cut the circuit to the neutral switch while it's running will the engine simply cut out?

[Pbodsw]

I've seen vehicle trackers that can remotely immobilize the ignition using a digital output to operate a 12v relay. You have something similar. In that case use Moonlighter's neutral wire suggestion and break it's circuit through the relay when the signal is sent?
https://www.rewiresecurity.co.uk/driver-identification
RewireDB1_copy_1070x974.png

[Moonlighter]

Fly by wire is not available on any Suzuki outboard less than 115hp so thats not even an option.

Its an interesting concept to remotely activate “safe mode” or similar and it will be interesting to hear if you figure out a (economical) way to do it.

Apart from “safe mode” the engines also have a neutral throttle switch on them. Simple on/off switch. If the ecu doesnt see a signal from that switch when the engine is put into gear it will limit rpm to around 3000revs to prevent the engine being over revved in neutral. Maybe you can figure a way to override that switch remotely …..

[benmbh]

We run a hire fleet using DF40A and a few DF20A's. I have GPS modules on the vessels that can activate a 12v signal based on certain conditions and i'm looking for a way in which I can somehow reduce the performance of the engine.

Our use case would be something like this. GPS shows customer is speeding, they don't answer their phone, we activate a signal, engine goes into limp mode, customer has to call us.

Any kind of advice would be appreciated. I thought a way to put the engine into limp mode or troll mode could potentially solve the issue. We use mechanical cables, no fly by wire at this stage although if there is a more elegant solution using FBW i'm interested for the future.