Korkie
Active Member
- Feb 2, 2016
- 1,331
- Boat Info
- 2006 340 Sundancer, Garmin 7610, xHD 24 Radar, VV703, SeaStar Hydraulic Steer, Shadow Drive AP
- Engines
- Mercruiser 496 Mags
Bravo III Drives
Sorry for the length, but want to give as detailed a description as could. 2006 340 496mags Br III drives - 900 hours. Bought the boat last year and has been doing great. Survey on purchase revealed only minor issues, mostly cosmetic. Approx 3 weeks ago started getting Fault code 40 on Strbd engine (MAT ckt lo) This started occurring intermittently than became constant. Checked manuals, stated bad sensor or short in circuit. Swapped sensors in motors with no change. Still getting Fault. Fault would occur sometimes at start up and sometimes not until after running for a few minutes. Also occur when reducing throttle coming off plane. (2 beeps / minute) It would also sometimes just stop and clear on its own.
Next came Port Fault 160 (Prt EMCT ovrht) at higher (3800-4000) rpms. Not knowing when impeller on that motor done, even though promised maintenance records at purchase, changed pump and impeller to Hardin Marine Gen 7 stainless pump. Took out, same problem. Since indicated exhaust manifold ovrht, took hoses off both manifolds and found one side partially obstructed with soft mud. Flushed manifold and fitting (on bottom) as well as could and re assembled, hoping that was problem. Also, last season, I completely removed and cleaned heat exchangers on both motors. Took her back out. Still getting the Fault 40 MAT, pretty constant on start up now. Up on plane with usual power, gauges all normal, cruising at 3500 or so, all good. Then took her up to 3800-4000 and OMG alarms went crazy. I got 11 alarms within 1 minute, with several sounding at one time. Power went to idle only. After several minutes of idling, it would let me apply throttle and I actually got back up on plane for the short (1/2 mile) run to my creek. The other thing that started shortly after the MAT FAULT is that when up on plane at 3500 or so rpms, the STBD motor rpms would decrease to about 3150 or so for 15 - 30 seconds and then go back up to 3500 only to drop down again and go back up, continuing this throughout the run. Also, came down off plane one time and on putting into creek at 1000, the STBD motor hadn't thrown the MAT fault, but then it increased its rpms to 1250 and threw the fault at the same time.
Once back on lift, history showed this list of faults: STBD FAULT 210 - Neutral overspeed / STBD FAULT 160 - prt emct ovrht / STBD FAULT 179 - stb emct ovrht / PORT FAULT 179 - stb emct ovrht / PORT FAULT 9 - Guardian / PORT FAULT 19 - overspeed / STBD FAULT 19 - overspeed / PORT FAULT 160 - prt emct ovrht / STBD FAULT 9 - Gaurdian / STBD FAULT 40 - mat ckt lo / SYSTEM VIEW FAULT - ambient temp ckt Hi.
With all of that, my STBD motor wasn't giving me any issues at all before cleaning out my PORT motor exhaust manifolds. All of the STBD ovrht, etc fasults were new as well as the ambient temp fault.
Been researching through the forums, and only info I can find is members having similar issues and it was actually the Smartcraft throwing false faults. I also read that some fixed it with a SMARTCRAFT SENSOR RESET, but cannot find any info as to how this is performed. Did see some did a total system reset, but want to stay away from that if possible since seems to require some re calibrations, etc. I live in an area where there is limited Mercury techs / marinas, so they are backed up with a 3 week wait just to get in.
I have had input from several sources and in addition to the new port raw water pump and cleaning the port exh manifold I tried swapping the throttle position sensors, no change in rpms variation. Stayed with STBD motor. Changed the MAT (new), also no change. I checked, cleaned and tightened my grounds last season, will do that again, but they looked good visually.
Any insight / direction on things I can do to troubleshoot, etc while waiting for the tech to come available would be greatly appreciated.
I am usually a pretty good detective figuring these things out, but this one totally has me baffled.
Next came Port Fault 160 (Prt EMCT ovrht) at higher (3800-4000) rpms. Not knowing when impeller on that motor done, even though promised maintenance records at purchase, changed pump and impeller to Hardin Marine Gen 7 stainless pump. Took out, same problem. Since indicated exhaust manifold ovrht, took hoses off both manifolds and found one side partially obstructed with soft mud. Flushed manifold and fitting (on bottom) as well as could and re assembled, hoping that was problem. Also, last season, I completely removed and cleaned heat exchangers on both motors. Took her back out. Still getting the Fault 40 MAT, pretty constant on start up now. Up on plane with usual power, gauges all normal, cruising at 3500 or so, all good. Then took her up to 3800-4000 and OMG alarms went crazy. I got 11 alarms within 1 minute, with several sounding at one time. Power went to idle only. After several minutes of idling, it would let me apply throttle and I actually got back up on plane for the short (1/2 mile) run to my creek. The other thing that started shortly after the MAT FAULT is that when up on plane at 3500 or so rpms, the STBD motor rpms would decrease to about 3150 or so for 15 - 30 seconds and then go back up to 3500 only to drop down again and go back up, continuing this throughout the run. Also, came down off plane one time and on putting into creek at 1000, the STBD motor hadn't thrown the MAT fault, but then it increased its rpms to 1250 and threw the fault at the same time.
Once back on lift, history showed this list of faults: STBD FAULT 210 - Neutral overspeed / STBD FAULT 160 - prt emct ovrht / STBD FAULT 179 - stb emct ovrht / PORT FAULT 179 - stb emct ovrht / PORT FAULT 9 - Guardian / PORT FAULT 19 - overspeed / STBD FAULT 19 - overspeed / PORT FAULT 160 - prt emct ovrht / STBD FAULT 9 - Gaurdian / STBD FAULT 40 - mat ckt lo / SYSTEM VIEW FAULT - ambient temp ckt Hi.
With all of that, my STBD motor wasn't giving me any issues at all before cleaning out my PORT motor exhaust manifolds. All of the STBD ovrht, etc fasults were new as well as the ambient temp fault.
Been researching through the forums, and only info I can find is members having similar issues and it was actually the Smartcraft throwing false faults. I also read that some fixed it with a SMARTCRAFT SENSOR RESET, but cannot find any info as to how this is performed. Did see some did a total system reset, but want to stay away from that if possible since seems to require some re calibrations, etc. I live in an area where there is limited Mercury techs / marinas, so they are backed up with a 3 week wait just to get in.
I have had input from several sources and in addition to the new port raw water pump and cleaning the port exh manifold I tried swapping the throttle position sensors, no change in rpms variation. Stayed with STBD motor. Changed the MAT (new), also no change. I checked, cleaned and tightened my grounds last season, will do that again, but they looked good visually.
Any insight / direction on things I can do to troubleshoot, etc while waiting for the tech to come available would be greatly appreciated.
I am usually a pretty good detective figuring these things out, but this one totally has me baffled.
