Mercruiser 3.0 PCM-09 Code 3050

[jnelsonusmc]

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

Is the O2 loop supposed to be closed?

Bank 1 O2 Loop Status............................ CLOSED
Engine Air Inlet Pressure.......................... 17.7 inHg
Bank 1 CAT Intake O2 %............................ -12.0
Barometric Pressure................................ 29.8 inHg
Bank 1 CAT Outlet O2 %............................ -12.0

Bank 2 O2 Loop Status............................ CLOSED
Bank 2 CAT Intake O2 %............................. 21.0
Bank 2 CAT Outlet O2 %....................... 21.0



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

 

[alldodge]

Hey @muc we could use your insight

 

[Bondo]

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.

Ayuh,..... Welcome Aboard,...... While I don't do 'puter controlled motors,.....
I don't see that anybody has checked the fuel filter for things other than clean fresh gasoline,......

 

[jnelsonusmc]

Bondo - I did hook up an aux tank to ensure good fuel was running through and I did replace the fuel water separator filter when I installed new fuel pump.

 

[Fun Times]

While this may or may not help all that much with this situation in question, the following link is a section of a OEM service guide I just stumbled upon to help us learn some things on regarding the PCM 09 and Emissions Control Overview system. Need a place to put it for saving.

http://download.brunswick-marine.com/filereader/file/pdf/5/enen/mercruiser/gasoline/8m0086113/8m0086113_2b.pdf

 

[jnelsonusmc]

While this may or may not help all that much with this situation in question, the following link is a section of a OEM service guide I just stumbled upon to help us learn some things on regarding the PCM 09 and Emissions Control Overview system. Need a place to put it for saving.

http://download.brunswick-marine.com/filereader/file/pdf/5/enen/mercruiser/gasoline/8m0086113/8m0086113_2b.pdf

Thank you very much for the response, I looked over the OEM guide and provide a few pointers for me but nothing to narrow down a real resolution to the issue. Unfortunately, everything seems to be pointing to a bad Catalyst.

 

[mvn]

Just because the O2 sensors were replaced, you still need to verify them. Try swapping them from side to side before contemplating the replacement of the catalyst. They don't look right.

Mark

 

[jnelsonusmc]

I have been doing some more research and from what I can put together if the CAT intake O2 % is the same for intake and outlet this is an indicator that the CAT is bad. Can anyone confirm or correct me on this please?
Bank 1 CAT Intake O2 %............................ -12.0
Bank 1 CAT Outlet O2 %............................ -12.0

 

[mvn]

Are your intake O2 readings varying?

 

[mvn]

Your Diacom software package should be able to perform O2 sensor performance tests as well as a number of other tests. Can you do a cylinder (injector) cutout test? What do your fuel trim numbers look like?

 

[mvn]

Oops, just realized this is a 3.0L engine so only 1 bank with a total of 2 oxygen sensors, upstream and downstream. Safe to assume bank 2 data is to be ignored? Can your Diacom system graph O2 sensor voltages? Upstream should oscillate and dow stream should be relatively steady when in closed loop mode.

 

[jnelsonusmc]

Just because the O2 sensors were replaced, you still need to verify them. Try swapping them from side to side before contemplating the replacement of the catalyst. They don't look right.

Mark

Mark -
Thank you for the recommendation, I will post back results once I get a chance to do that this week after work and re-run the Diacom diagnostic.

Jim

 

[jnelsonusmc]

Oops, just realized this is a 3.0L engine so only 1 bank with a total of 2 oxygen sensors, upstream and downstream. Safe to assume bank 2 data is to be ignored? Can your Diacom system graph O2 sensor voltages? Upstream should oscillate and dow stream should be relatively steady when in closed loop mode.

Mark -
Here are the results from the first scan - Ony 2 O2 sensors so not sure what bank 2 is showing below. Oil pressure shows 0.0 psi but gauge shows 50 psi - still learning the Diacom package.

Engine Speed........................................ 696 RPM
Bank 1 Long Term Trim.............................. 15.0
ECT Temperature..................................... 145 °F
Bank 1 Short Term Trim.............................. N/A
Intake Manifold Pressure............................ N/A inHg
Bank 1 O2 Loop Status............................ CLOSED
Engine Air Inlet Pressure.......................... 17.7 inHg
Bank 1 CAT Intake O2 %............................ -12.0
Barometric Pressure................................ 29.8 inHg
Bank 1 CAT Outlet O2 %............................ -12.0
Intake Air Temperature............................... 88 °F
Bank 1 Exhaust Gas Temp 1........................... N/A
Oil Pressure........................................ 0.0 PSI
Bank 1 Exhaust Gas Temp 2........................... N/A
Throttle Lever Position............................. 0.0 %
Bank 1 Exhaust Gas Temp 3........................... N/A
Commanded Throttle Position......................... N/A
Bank 2 Long Term Trim.............................. -7.0
Throttle Blade Position............................. 0.0 %
Bank 2 Short Term Trim.............................. N/A
Low Idle Switch...................................... ON
Bank 2 O2 Loop Status............................ CLOSED
Spark Advance....................................... 5.0 DEG
Bank 2 CAT Intake O2 %............................. 21.0
Battery Voltage................................... 14.60 VDC
Bank 2 CAT Outlet O2 %............................. 21.0
Ignition Switch Voltage........................... 14.60 VDC
Bank 2 Exhaust Gas Temp 1........................... N/A
Fuel Level.......................................... 0.0 %
Bank 2 Exhaust Gas Temp 2........................... N/A
Engine Operating Hours............................ 199.5 hrs
Bank 2 Exhaust Gas Temp 3........................... N/A
Fuel Flow Rate...................................... 0.7 GPH
Engine Coolant Pressure............................. 0.0 PSI
Sensor Supply Voltage 1............................ 5.00 VDC
Sensor Supply Voltage 2............................ 4.95 VDC

 

[jnelsonusmc]

Are your intake O2 readings varying?

I posted the full scan results to one of your threads - they are no varying - same for input and output.

 

[alldodge]

Guess @muc must be tied up, he normally comes along to help

It's like your not getting any response from the sensors to the PCM (bad or broken connection). Yes their should be a difference between O2 going in and O2 coming out. Don't understand the No exhaust Temp, guess the sensor isn't there?

Looking at motor on line I'm seeing 7 different Manuals and all show different serial number breaks for the EC. There has been several part number changes for the motor which could mean it doesn't have the sensor

 

[alldodge]

There are bench test for the O2 sensor, measuring ohms and also voltages.
Could remove the sensor, connect voltmeter to sensor leads, turn power ON and check voltage. With power still ON could heat sensor up with propane torch. Every time the torch is on the sensor the voltage should quickly change between 0.1V to 1.0V. The Diacom should also see the change

 

[dubs283]

Pre O2 and post O2 readings are the same.

With having both O2 sensors replaced recently my wag is the catalyst has failed. Without the catalyst the pre/post O2 numbers would be the same, like your situation.

Time to check your catalyst

 

[mvn]

Your Long Term fuel trim is way too high according to the data. The ECM thinks it sees a lean condition due to the upstream O2 sensor reading so it's throwing more fuel at it. But the data is showing a negative oxygen value......odd. I would do an injector cutout test using the Diacom tool to see if you can identify the misfiring cylinder due to injector issues.

I would also want to look at the upstream O2 sensor voltage to see if the sensor is seeing a switching rich/lean condition when in closed loop.

Have you checked your spark plugs?

A lot of conflicting data here, in my humble opinion.

 

[mvn]

Another question......Can you get access to the freeze frame data that was captured automatically by the ECM when the trouble code was set?

 

[jnelsonusmc]

Another question......Can you get access to the freeze frame data that was captured automatically by the ECM when the trouble code was set?

Thank you for all the things to check, I will do my best to go through all the suggested items tomorrow. Still learning the Diacom diagnostic package need to sit down and review the manual completely so I can ensure I am running the correct test. I will report back my findings as soon as I can.