BF175 Alarm

Aliboy - did you ever try running without the t-stats or new ones installed? Earlier I speculated that you just may have a slow opening t-stat. That still seems like a distinct possibility. By turning the engine off, then restarting, you may be allowing the t-stat time to open up fully.

The thermostats were both pulled and tested (one replaced) during the service just prior to this happening. I don't really think that we have a real overheat situation, but I agree with you that I should try running without them to check. Will tackle that tomorrow I think.

yes you can try with swapping ECU , once its happen to us also, bit you mentioned at idle and just after start engine and after sometime its giving alarm. it can be over heat. why dnt you open the top cover and check exhaust manifold at same time (by touching ) .it happen many time ,one side of manifold getting over heat but when you accelerate it goes and never come till next trip.

wajira

Personally, I think that you have a wiring problem. The cold and hot thing is what makes me go there. When the wiring is cold....the connection isn't so great. As things warm up and EXPAND, "better" contact is made and no alarm.

But, it could, as well, be a poor connection inside the ECM as you suspect. I don't think there is any "keying" of one ECM in particular to any one engine. Swapping them should be perfectly fine. The one dynamic this may set up is that each computer has adaptive processing to compensate for wear in certain items like TPS and IAC. So...on initial start up after a swap, the idle may be a bit rough or "hunting" as the "new" computer "learns" the sensors. That should smooth out fairly quickly.

Then, if the symptom transfers to the other engine...you've found it. If not....I would get to looking at the wiring between sensor(s) and ECM.

It would help if you knew the "strategy" for turning on that alarm. Is it from the one sensor only? From any of the three? Would it alarm if one sensor were not reporting in conjunction with the others as expected? That sort of thing.

I don't know or I would share it with you.

Merry Christmas.

Next chapter in the saga. Didn't get a chance to pull the thermostats due to bad weather. Have had 3 customers out since then and the alarm hasn't gone off. I am taking the boat out for an 'extensive sea trial' (mmmmm - fresh fish with scallop mornay) tomorrow to see if I can get the alarm to happen again. Will report back

So, idling out of the marina this morning and the alarm goes off. Turn off engine and restart. Don't see the alarm again all day despite stopping 6 or 7 times to shift fishing spots etc. Pan fried fish with scallop mornay for lunch on the boat, and a bag full of fillets for the guys I was training today. Blowing 25 gusting 35knts most of the day so wasn't a bad result in difficult conditions.