Expert Request: DF40A, instantly get overheating alarm once start

[Thach2264]

Hello all-

I need expert advice on my 2015 DF40A. I bought it used and finally got it to run, but there's one issue I cannot resolve. The motor will start up ( sit over night) without hesitation, BUT immediately the overheating alarm also come on as well. Check engine will flash code 1-4, but no light on temp sensor though.

Things I have done:
New impeller, clean water passages ( I removed the head) so all water passage is good. Strong pee stream. Have run in barrel and direct connect from the water pickup tube (with lower removed, not flush side).
Test IAT and temp sensor resistant (within range), check for 4.0V+ from ECM confirmed. I even ran it with a potentiometer set at 2.2kohm = 75*F to eliminate the gradient temp change. I also ran it for 20min and check head temp from the temp sensor and it read steady at 620ohm = 130*F. And check continuity from IAT and temp sensor to pin before ECM =good.

What I am 99% sure, I do not have cooling issue, It's not cause by gradient temp change(I hope), my temp sensor is good, IAT sensor is good.

I thinking one of the wires are short/intermittent or I've a bad ECM. Any suggestion will be appreciates.

thanks all.

 

[Thach2264]

update: My 2015 DF40A with an 2018 60HP ECM, keep getting ghost overheating alarm. I checked EVERYTHING. Finally I got the Suzuki sds diag tool, and it show that I have an "ECM and Harness are Unmatched" every times I start up and limited me to 3krpm.

Question: is this fixable by re-working a few wires? Can the ECM be reprogrammed at Suzuki to match?

Also, does anyone have the ECM terminal pinout for a 2015 DF40a and a 2018 DF60A to help diag my ghost overheating issue.

Also looking to buy a 2018 DF60A harness or a 2015 DF60A ECM if anyone have just laying around (yes I've search eBay).

Thanks all.


And no I do not have the orignal DF40A ecm.