What's new

DF140 Electrical Issue

JoeRocket

JoeRocket

Registered Member
Last week a friend lost one his engines on his Twin Vee. They are 2016 DF140's
The engine would not trim or or start, acted like it had a weak battery or bad ground. Turns out one of the primary ground cables corroded off of the terminal at the battery.
Was a pretty easy fix.
Since that happened it has intermittently thrown numerous fault codes and alarms, up to 20 at a time :rolleyes:. Not just for the engine but also for the throttle, trim, gearshift. Seems like its pretty much all of them.
Any ideas on where to start looking?
All hints appreciated!
Thanks
 
Things to check

Suzuki's are very sensitive to voltage. You absolutely need to make certain your batteries are good. You needto ensure they are fully charged and do a load test on them, only way. Each engine needs its own starting battery.

Check cables to the engine and battery, they do corrode as you indicated and a very small amount of corrosion will end a happy day fishing before it starts

Disconnect the the positive and negative from the battery overnight to see if this corrects the issues.

Engine needs to go to Suzuki so they can use their fancy computer and re-initiate or calibrate all the sensors. Just like cars, these engines are ran by sensors. Dead battery itself can give you error codes, but even after the issue is fixed and in some cases, it "confuses" the ecu.

Let us know what happens. Good luck
 
Last edited:
Suzuki's have what's called "the white wire". This wire should be going directly from under the cowl of the outboard to the battery side of your battery switch, or directly to the battery with a fuse. Basically, that wire keeps the engine computer stable during startup and under heavy electrical loads. If that wire has become corroded, broken or compromised in some way it will do everything you just mentioned.
 
Joe,
Check the connections / securing nuts to the back side of the A-B Switch. And I highly recommend using some small split washers to help keep them from getting loose from all the wave pounding the entire boat takes.

Basically any drop below 10.5 VDC will put pretty much any ECU into a state of confusion and or force it to run on what is called a default limp home mode.

Also, keep up updated with your Root Cause findings when you know :cool:

Thanks!
Dave
 
Ok whats the A-B switch? I have not yet identfied the "white wire".
The electrical system on this boats a mess. We have found numerous issues while working this discrepany. And I have worked thru other issues in the past.
Latest find was two primary grounds that were on there last leg to one of the other batteries. Will recrimp and let you know tommorow.
The boat is equiped with a pretty nice simrad setup, it shows the vsupply on the number 1 battery as low frequently getting below 10.
Thanks for the support!
 
281469_1500.10062019030024.jpg
 
Right, so it's setup with three battery switches. Lets call them A B C
A is on off
B is 1 both 2 off
C is 1 both 2 off
1 is definitely the week link in the system
 
Replaced several primary ground terminals various blown fuses, and melted wires.
I beleive the "white wire" on this rig comes from the ignition switch. Can confirm that its not on the batteries.
There is one unidentified power wire to one terminal of one battery switch that goes to a 3 amp fuse. The fuse is good but I have not been able to identfy the circuit it powers.
Still mutiple alarms, I now think its ALL the alarms the ECU can give.
Also the engine would not make power several times (this was also intermittant). However I did replaced a confirmed faulty o2 sensor and some suspect injectors since then.
Today I noticed that the Suzuki interface cable was really hot to the touch, and that the problem engine did not show up on the network. The other interface cable was normal room temp. The alarms come on after about 5-10 minutes of operation.
Dissconected the interface cable from the backbone and did a sea trial, engine had no issues. Also no alarms since it was disconnected.
Clearly the interface cable can pull data from the ECU, the question is can it interfere with ecu operation as well?
These multiple level problems are very difficult to work any input is appreciated!:oops:
 
I can see where leaving the test leads in place without being actually connected to the tester "could" cause an issue by not completing the circuit back to the ECU. As such, creating a feedback which could lead for a little heat and havoc... Shocked that if it got that hot, it did not scramble the ECU and shut everything down forcing a ECU replacement so consider yourself lucky, those ECU's are usually very expensive :eek:

Be that as it may, you would really need to either check with a Zuke Tech, this or make a deep dive in the manual on ECU tester operation and see what is recommended for that year and model? Possible that unless the tester leads are connected to the box, that they should not be installed in the harness? Again a Zuke Tech or some heavy Google Searches on the subject might come in very handy!

I have seen though, what I call "Blind Part replacements" based on error codes from out of spec Engine / voltage operation. I would not change sensors of any kind, until I know for sure, that you have a secure wring harness (all the grounds are clean and secure) and the system is truly operating as designed voltage wise. Seen my share of (so called) false error codes and swapping out of TPS, O2, coolant, ETC. ETC.. Sensors with no impact other than cleaning out the wallet ;)

Hope this helps and keep us updated!
 
Ok update time...
Replaced the engine interface cable. So far no error codes. And the engine now shows up correctly on the network!
This boat has had layer upon layer of electrical and fuel issues.
Lets hope I got it on the run!
 
You must log in or register to reply here.

Similar threads

Dave LeGear
VRO Oil Pump information
Replies
2
Views
24K
Dave LeGear
Dave LeGear
Back
Top