2008 VTX TROUBLE CODES SPN: 65567 & SPN: 65568

[SamoraRacing]

2008 VTX WAKESETTER 340 MONSOON TROUBLE CODES SPN: 65567 & SPN: 65568

SPN: 65567 OXYGEN SENSOR A1 RESPONSE FMI: ABNORMAL FREQUENCY OR PULSE

SPN: 65568 OXYGEN SENSOR B1 RESPONSE FMI: ABNORMAL FREQUENCY OR PULSE

I have been dealing with these two codes for 2 seasons now. I have replaced both O2 sensors, updated my cat temp sensors via the mod from Indmar. The boat seems to run fine with no issues with the exception of these two codes popping up giving me a alarm. I am considering replacing my MAP sensor along with trying to find any vacuum leaks, and the temp sensor. 

I have the freeze frame data from the Marine Service Report from DIACOM if anyone can help me trouble shoot this issue. Thanks in advance!

 

[CLT]

Did you ever figure out the issue?

[SamoraRacing]

Sorry for the delay. I have yet get a chance to get to the lake and trouble shoot it. I’m going to take a MAP sensor with me and try that. Are you having the same issue?

[SamoraRacing]

Bump

[SamoraRacing]

Can anyone help with this?

[csleaver]

I expect you have a MEFI5B ECM on your motor.  I can't find those codes in the MEFI5 book, but they are in the MEFI6 book.  There are several things that can cause those fault codes, but here are a few you can check.

First, check the fuel pressure.  It should be around 58-62 PSI.  If it is too high, or low, the fuel mixture will be too rich, or lean, and the cause the O2 sensors to not change voltage quickly enough for the fault threshold.  A vacuum leak or exhaust leak can also cause this.  Leaking or clogged fuel injectors can cause a similar issue.

It could be as simple as coked, or carbon covered, O2 sensors.  If the boat is run with excessive weight, or at high altitude with too large of a prop, it can coke the sensors.  Running unloaded above 4000 RPM for 15 minutes or so will often burn the carbon of the sensors.

Moisture or corrosion on the O2 sensor harness plugs can cause problems.  The low reference circuit on the O2 sensor harness could have high resistance to ground (more than 5 ohms), or shorted to voltage.  The O2 signal circuit could be shorted to voltage or ground.  The ECM could have an internal open or short on that circuit causing the fault.

There's a lot that can cause O2 sensor issues, so I usually start with the easier/cheaper stuff and work my way to the harder/expensive stuff.

I worked on a 2012 Malibu with a similar issue last year, it passed every test I performed and had new O2 sensors installed.  Indmar recommended a newer O2 sensor that they had available that took care of the problem.  Eventually the ECM and harness had to be replaced due to other intermittent problems.  I think the ECM may have been submerged, but I couldn't verify it.

[SamoraRacing]

Thank you so much for your help. I’m going to look for exhaust leaks since I had both manifolds off for maintence. After I put the boat back together this code popped up. I combed both manifolds for carbon build up this weekend and found nothing. I’m going to pressure up both exhaust manuifolsa with a shop vac and stray soapy water on the key spots that could possibly leak. My fuel pressure according to Diacom is 147.9 psi which is high compared to your number. I’m wondering if my number is high cause the motor was off while being scanned. 

Can you tell me what side B1 Bank1 is on my motor. I’m assuming it is the side where cylinder #1 is located. 

Thank you for your help, I’ll be looking g for your reply. 

👍🏼

[csleaver]

The fuel pressure on diacom will not be correct, the motor does not have a fuel pressure sensor.  You will need to use a fuel pressure gauge and connect it to the test port on the fuel rail near the HVS/distributer.  Bank 1 is the starboard side on a vdrive boat with a GM engine, it is the side with the number one cylinder.

[SamoraRacing]

Thank you so much for your help. I’m going to look for exhaust leaks since I had both manifolds off for maintence. After I put the boat back together this code popped up. I combed both manifolds for carbon build up this weekend and found nothing. I’m going to pressure up both exhaust manuifolsa with a shop vac and stray soapy water on the key spots that could possibly leak. My fuel pressure according to Diacom is 147.9 psi which is high compared to your number. I’m wondering if my number is high cause the motor was off while being scanned. 

Can you tell me what side B1 Bank1 is on my motor. I’m assuming it is the side where cylinder #1 is located. 

Thank you for your help, I’ll be looking g for your reply. 

👍🏼

[SamoraRacing]

Ok I’ll check the fuel pressure and exhaust leaks this weekend when I get back to the boat at the lake. I’ll keep you posted. Thank you. 

[SamoraRacing]

What is the best way to test for a vacuum leak?  Run the motor and spray carb cleaner around the intake manifold and see if RPM’s increase?

[csleaver]

That works, but it can be dangerous, and if the carb cleaner spray gets drawn into the throttle body it can also effect the RPM and give a false test result.  Fluctuations or low actual throttle position readings can indicate a vacuum leak.  Using a vacuum gauge spliced to the intake port and map sensor is another way.  Just use the guide with the vacuum gauge or download one to see proper and improper readings.

[SamoraRacing]

Ok I’m back with a update. I found no leaks in the exhaust system. I did not get a chance to look for a vacuum leak on the intake. 

What I did find was a loose PCV Valve. I ran the boat and eventually lost the 65567 code on its own with out clearing it with Diacom. I ran the entire weekend and this code never popped back up. Note I did not clear it with DIACOM, it cleared itself. 

Now the only code left was 65568 on bank one. This is when I started looking for leaks in the exhaust system etc. Note, I found no leaks. So I just cleared this code with DIACOM, and this code never came back.

I have had the boat on the water for around 20 hours, and it remains code free. It also seems to be getting better fuel economy. 

I plan on running the boat this weekend with DIACOM hooked up and watch to make sure it’s going into closed loop. 

I dont know why the 65568 never cleared on its own; do you have any input here?  At any rate the boat seems to be running as it should, code free!

thamk you so much for your help. I hope this helps anyone fighting these 2 codes. ✅✅✅👍🏼👍🏼👍🏼

[CLT]

I've been getting the same code 65568 FM1:8 on an off for over a year now. I tried new o2 sensors and even a less sensitive O2 sensor 556162D $250 that Indmar suggested and then did the other side and now no more codes

We don't surf.

I had my share of issues with this 2012 Malibu VTX.

Edited August 31, 2018 by CLT

[csleaver]

SPN 65568 FMI 8 or 10, refers to the bank 2 sensor 1, which is the 2,4,6,8 cylinder bank on a GM engine, port side on a vdrive, pre-cat sensor in the exhaust manifold.

[SamoraRacing]

11 hours ago, csleaver said:

SPN 65568 FMI 8 or 10, refers to the bank 2 sensor 1, which is the 2,4,6,8 cylinder bank on a GM engine, port side on a vdrive, pre-cat sensor in the exhaust manifold.

I finally cleared the code. I found a loose connection of my pcv valve to the valve cover port side. You might check the hose that runs from the intake to the Pcv valve. I’m thinking it was detecting a vacuum leak this throwing these codes. Thank you for the help. Hopefully the code wont be back. 

Edited July 10, 2018 by SamoraRacing

[picknicker]

I had the SPN 65567 FMI:8 and SPN 65568 FMI:8 on my 22 MXZ from 2012 with a Indmar 6.0L engine. I was able to solve the problem by cleaning the four o2 sensors and resetting the error code in the ecu. Maybe the information is useful for someone.

[CLT]

On 7/9/2018 at 9:56 AM, CLT said:

I've been getting the same code 65568 FM1:8 on an off for over a year now. I tried new o2 sensors and even a less sensitive O2 sensor 556162D $250 that Indmar suggested and then did the other side and now no more codes

We don't surf.

I had my share of issues with this 2012 Malibu VTX.

Yep it's been a month of use with out a 02 sensor code. By the way I used the part numbers off the $250 sensor to order one for only $60.

[WY22MXZ]

Can you share that pn for the $60 sensors?

 

[CLT]

 Denso GM 12589321 

[schippers20]

On 7/23/2019 at 8:27 PM, CLT said:

 Denso GM 12589321 

Been chasing this code for 3+ years…+1 on the above Denso sensors…code cleared after an hour or so on the lake this weekend.

Edited August 15, 2022 by schippers20