Mercruiser 3.0 PCM-09 Code 3050
 

Hello, I have a 2011 Mercruiser 3.0 inboard that kicked off a code 3050 Catalyst 1 Inactive FMI: 1 Data valid but below normal Occurrences: 1 and engine went into Guardian Protection with a previous fault code of 521009 Merc Fault 9 FMI 31 Not Available. The 3050 is active code and the 521009 is listed under previously active trouble code list. I am running the Diacom diagnostic ver 3.3.6 I bought the Diacom package after local marine mechanic charged me over 4k and boat still does not run right. Boat starts right up, idles and runs good put it in the water under load and right at 1500 to 1800 rpm engine goes into guardian protection mode within 2 mins. I installed New distributor cap and wires, New start switch, New starter relay, New plugs, thermostat; Fuel pump and Water pump; marine mechanic installed New O2 sensors and New TP sensor. All OEM parts used. Boat had been sitting for a while when I bought it reason for the items I replaced. Took it out and engine went into Guardian Protection mode after 2 mins of running at 2500 rpm so took it into local mercruiser marine mechanic who replaced the O2 and TP sensors.

Engine has 200 hours on it

PCM-09

Mercruiser 3.0 MPI 135 A1

Drive Number 1A277619

Codes 3050 and 521009

Diacom ver 3.3.6

Needless to say after a 4,500 bill from the marine mechanic and engine is still not running correctly, I am hoping that someone in the forum can help me fix this myself. I am not a marine mechanic but have above average mechanical abilities and hopeful with help from the forum and the Diacom diagnostic I can get this thing running right. Any assistance would be greatly appreciated.


Regards,

Jim Nelson

How long is ‘sitting for a while’ ? The only thing that degrades, really, from sitting is the fuel. Unless, sitting in salty sir environment.

I'm not able to find the code, but in my draft copy of the PCM manual the 30xx numbers all deal with electrical faults (shift, fuel pump fault, throttle control lost).

Many times the issues deal with voltage levels being low. Check that 5V is actually 5V

If another isn't able to help, suggest posting on the iBoats forum and we can see if MUC is available to help. MUC is a retired master Tech

Previous owner said it had been sitting for 6 months - the parts I replaced was just for peace of mind.

Sensor Supply Voltage 1............................ 5.00 VDC
Sensor Supply Voltage 2............................ 4.95 VDC

Sensor Supply Voltage 1............................ 5.00 VDC

Sensor Supply Voltage 2............................ 4.95 VDC

Thank you for the iboats recommendation.

the 3 liter is a little 4 cyl you can old school it and throw a carb on it and it will run very well for a zillion hrs remember whats old is new again might work here but spending 4500 on a 3 liter is questionable? the replacement cost is less than that

Have you tested the battery? PCM 09 is very voltage sensitive and will throw many faults if there’s a supply voltage issue

Yes - system voltage is good.
Ignition Switch Voltage........................... 14.60 VDC

thank you - that is beyond my mechanical and financial means currently.