SPN 105

[SanDiegoM240]

My 2020 M240 threw an SPN 105 High Air Intake alarm.  What is this?

[csleaver]

It can be serious.  If the air intake for the supercharger gets too hot it can be damaged and that can also cause engine failure.  Don't drive the boat for very long, or above idle speed, until it is fixed.

There is a fuse block for the CAC (charge air coolant) pump on the starboard side of the engine near the pump.  Make sure the fuses are good, that the electric CAC pump is working, that there is enough coolant in the aft reservoir, and that the raw sea water pump is pumping water through the cooling system.

[SanDiegoM240]

Thank you csleaver. I looked at the fuses, but did not see one labeled CAC, but will go back down and take a closer look.  Coolant levels are good and ensured the strainer was clean.  I did have a little material in the strainer and when I look at the intake port on the underside of the boat, there was a little grass in it as well, it did not seem like enough to restrict water intake much.  I took some photos of the screen and it shows at the time of the alarm, the coolant was 165 degrees and the intake air temp was 168 degrees, so those temps seem normal.  Hmmm.

[csleaver]

Location of CAC pump, fuses, and relays.

https://www.dropbox.com/s/8hhghkpaw3cmt3r/LT4_CAC Pump and Fuses.jpg?dl=0

You can usually see coolant being pumped into the aft reservoir when the engine is running and the pump is working.

Edited April 30, 2023 by csleaver

[csleaver]

Low system voltage or a loose/corroded main ground cable connection, loose battey connections, or loose power distribution post connection, could cause a voltage drop which would make the sensor give a false reading. 

[SanDiegoM240]

Upon further inspection, it was the fuze.  It looked fine, but once I replaced it all was well again.  Thank you all for your assistance.  

[csleaver]

Glad to hear it is working.