temp light stays on

[Zarpman]

Have a 90HP Suzuki 2008 How many heat sensors are installed on this engine? I located one on top of cylinder head. the reason I asked is because (1) I changed the water pump (2) put in new thermostat (3) water flow great in a tub however the temp light does not go off.Zarpman

[Harper]

2008 DF90 Suzuki Marine Outboard SENSOR Diagram and Parts

I believe there's two. One in the cylinder head, one exhaust gas temp. I think the parts diagrams for the DF70-DF140 are misleading, looking like there are three, instead of two. You'd do well to get yourself a service manual.

[Zarpman]

Temp light stays on

Thanks Mike, According to Suzuki Manual I just bought they say there are two like you said. A cylinder head temp and exhaust temp sensor which I will test this weekend. thank You for your input and taking the time to read my post. Wish you and family a safe Holiday. Zarpman

[Zarpman]

temp light stays on

Well I removed both temp sensors and checked them with the OHM meter. High reading when cold and low reading at 160F like the manual says it should be. Can not understand what is making that light stay on. New thermostat, new water pump and water pee good flow. Light went on before all the replacements and it is still on. Why is it saying engine temp hot when it starts up cold? Running engine in a large tub also.Should I take lower unit off again and go over what I installed? Wits End Zarpman

[redlowrey]

When the engine is running the ecu is looking at the signal line voltage of the cyl head temp and the exhaust temp it runs between .1 to 4.6 volts, if it go's out of that scale the check engine light will flash a code. The same thing if you disconnect the plug at the temp switch and turn the key on the check engine light will flash the code. If the signal line voltage starts creeping towards it's upper limits between the two sensors the caution system will turn the temp light on and stay on. If the temp light is on when you turn the key on, My guess is one of the sensors is faulty. Get a very thin needle and push it down the side of the plug, turn the key on and check the signal line voltages of both sensors. with the engine cold both should be up near four volts and slowly drop down as the temp increases. Hope this information helps you..

[redlowrey]

I forgot to mention do's the rev limiter light come on with the temp light, if not it nay not be the sensors. The temp light has battery voltage on it all the time, the ecu puts the ground on it when there is a problem. Can you do a couple of tests, disconnect the battery for thirty seconds and hook it back up, turn the key on and see if the light go's out. Disconnect the temp sensor turn the key on, the check engine light should flash a 1 - 4 code.

[Zarpman]

temp light stays on

Thank You for giving me more information on this matter. What you say makes a lot of sense and I will try to work on it again after Xmas. It seems to me that the electric part of this system is to blame and like you said the temp light has a connection that is complete and causing it to stay on. I would take it to a mechanic shop however; I like to do things myself if I can.I will get back to you when I can to let you know what it was. Have a safe Holiday to you and your family. Red Lowrey Zarpman