smartCraft TPS sensor

[Thomas Connolly]

have a 2006 sea ray sun dancer 300 with twin 350 mercruiser mpi horizons. Starboard engine goes into guardian mode whether on plane or not. It doesn’t do this continually but it happens each time we take the boat out. It is showing TPS fault. Out on the boat the other day the starboard continued in guardian mode for about 45 min. I stopped the boat, shut both engines down for about 20 secs restarted them and got the boat on plane back to our marina. Began to beep and flash check engine TPS fault when I cam off plane. This has been ongoing for two seasons. I thought I had it resolved a couple of times only to have it resurface. As of now I have changed the impeller (aug 2017), temp sensor, water pressure sensor, had the pcm checked , no issues there, changed the IAC and the throttle position senso

 

[DarkJester]

Intermittent failures usually end up being a faulty or corroded connector, a bad wire/ground, or indeed a defective switch or sensor. I know you can put a meter on the TPS and check it, and I can't put my fingers on what it should read, but it should change linearly over the travel of the throttle. You may need to get a Merc Tech to put a laptop on it and see what actual codes are being processed by the PCM. Check your fluid levels, etc. SmartCraft is really pissy about fluids.

 

[Thomas Connolly]

Intermittent failures usually end up being a faulty or corroded connector, a bad wire/ground, or indeed a defective switch or sensor. I know you can put a meter on the TPS and check it, and I can't put my fingers on what it should read, but it should change linearly over the travel of the throttle. You may need to get a Merc Tech to put a laptop on it and see what actual codes are being processed by the PCM. Check your fluid levels, etc. SmartCraft is really pissy about fluids.

I check them regularly but will do so again today.

 

[Thomas Connolly]

Intermittent failures usually end up being a faulty or corroded connector, a bad wire/ground, or indeed a defective switch or sensor. I know you can put a meter on the TPS and check it, and I can't put my fingers on what it should read, but it should change linearly over the travel of the throttle. You may need to get a Merc Tech to put a laptop on it and see what actual codes are being processed by the PCM. Check your fluid levels, etc. SmartCraft is really pissy about fluids.

What are your thoughts about the instrument cluster causing this?

 

[DarkJester]

Interesting. I wouldn't think that the instruments would/could cause the engine to go into Guardian mode. I could see them throwing a code, etc. But actually taking control of the PCM and shutting the engine down sounds like a stretch. Not that it's impossible, but I would think it would be rare. Did you ever have a tech put the computer on it? If it went full Guardian and then you put the computer on it you should be able to see what caused the issue.
I would still throw a meter on sensors, especially the TPS. just to be sure it's good.
I would check it at both ends at the sensor and at the PCM.
The computer will tell you what the actual failure was, not just the Alarm.