evaluex

Friend of mine has installed almost new (< 50 hrs) 6.2 engines in his boat. Start & idles fines, but will not rev over 2200 RPM. ECM read out (Diacom) shows almost identical fault codes for both engines.

Sometimes 100% power available, afterwards only 90% => seems to be engine is going into guardian mode.

Warning Horn Output 65535 Sec an.
Sea Pump Pressure varies between 0,0 - 0,25- 75,50 ???

PITOT CKT LO Code is active
FUEL LVL CKT HI Code is active
STEER CKT LO Code is active
SEA TMP CKT HI Code is active
TRIM CKT HI Code is active

Apparantly no one seems to be able to solve this problem. Could this be a smartcraft non compatibility??

Attached the diacom ECM read outs

Anyone some good iedeas how to solve these problems?

txriverrat2001

All of the codes you listed are normal except for the Sea Temp Ckt Hi ......

Pitot Ckt Lo is normal as your probably not reading pitot pressure - I haven't seen one yet that has. fuel Lvel - same thing unless your feeding you fuel level to the ECM.

The most common one I find is the sea pump pressure as it will place the engine into guardian mode. If the scanner is inconsistent with the Sea Pump pressure - check the sensor on the pump for an old impeller peices plugging the hole or just replace it.

Dave_N

Looks to me like it may be due to a bad "In Gear" switch. If the PCM thinks your in neutral, it won't allow full RPM. It will go into Guardian Mode.

Looking at the stored Guardian fault, your looking at a snapshot of the last of the 52 times it went into Guardian Mode. The RPM is 4,066, and the engine is in neutral, so I think thats got to be it.

Dave

Dave_N

I just noticed that there is a "Shift Switch" Fault with a frequentcy count of 53, and the Gaurdian Mode has a frequency count of 52. It's pretty clear that's the problem.

Dave

evaluex

Hi Dave,

I was hoping you would come in on this tread

I found this fault codes but only on 1 engine, while both are having same problem (not revving up + 2200 rpm)

Any idea how we could test this (malfunctioning) neutral switch or temporaly leave it out / block it to see if problem will be solved?

Thx all replys

Falcon

Just unplug it! It will think it's in gear all of the time so it won't have neutral rev limit and some other details, but will run ok. Most of the time it's just that the switch isn't adjusted right.

evaluex

They already tried it before... still no luck

Besides the ECM reading on the other engine clearly shows "in gear" => meaning the gear switch works...

What's next to try ???

I'm really counting on you guys

lowfunds

all the codes you are reading are normal codes including the one that says sea temp. that is for a actual sea temp transducer. it has nothing to do with the engine. anything like that would be reffered as ect which stand for engine coolant temp. does this boat have smartcraft gauges. if not it uses all anolog gauge signals. check and make sure no one hooked up the trim sender harness to the digital plug on the back of the engine. also if it does have smartcraft i have seen people hook up the fuel guage plug to the positive side of the sender and the ground for the sender to ground plug on the engine and what happens is where the digital signal should only see a 5 volt reference gets 12 volt instead and it causes the engine to do funny things like this. after you have checked all of theses things try swapping the pcm with the other engine and see if the problem goes to that engine. have you checked all the obvious things like fuel pickup and fuel pressure. and have you compared your engine parrameters with the book and the other engine to see if something is not in secifications.

Dave_N

Forget about the other engine for a second and repair the known problem, the shift switch. Looking at the Diacom reports, there is no question that Guardian Mode is being triggered because the ECM thinks the engines in neutral.

If you disconnect the switch and the ECM still thinks it's in neutral, then there must be a short or something in that circuit. Fix this issue first!! Get the ECM to think it's in gear and then retest.

Are the engines connected to a Smartcraft display?

Dave

lowfunds

i think there is also a load anticipation switch too along with the shift switch.