Mercruiser Mag 350 guardian problem

[willf77]

Hi, I have a 2011 Mercruiser MAG 350 MPI Bravo, with a persistent guardian mode problem - we have replaced the throttle sensor as our Rinda Techmate was showing an error code, but the engine is still going into guardian mode. But at random speeds - sometimes at 2500 RPM, or sometimes at 4000 RPM. But always within 30 seconds or so after putting the throttle down. The alarm does not go off when revving the engine at idle. The Techmate is showing no error codes at all. ( FYI - the speedometer is currently not working and shows 70 MPH when the throttle is engaged. Can you help? Thanks

 

[AllDodge]

Have a serial number?

Do you keep the Techmate connected when Guardin starts and it doesn't tell you why?

Check the 5V power on the TPS, MAP or water pressure sensor

 

[willf77]

Serial number is 1A652676

Yes, techmate is connected and does not show any faults when guardian mode comes on.

Thank you for these suggestions!

 

[AllDodge]

Being a EC (cats) motor with motor in guardian look for
Voltage reading 14V or more
Water pressure (most common cause)

Can also be the IN-Gear switch. If motor thinks it's in neutral than around 2500 rpm it will sound the alarm. The switch is on the shift plate