Evinrude E-NATION, for those dedicated to water, power, fishing and fun
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Mate
Posts: 2
Registered: ‎06-26-2018

Air. Circuit fault and homogeneous mode

Was wondering if anyone can tell me what the repair is for a air circuit fault and if this has anything to do with my motor going into homogeneous mode. 2005 etec 225!!  When I try to take off my motor just bogs down. Had a mechanic friend hook it to a computer and he said the air circuit fault came up and the motor went into homogeneous mode as soon as I got on the throttle. He was unsure about both of these

Admiral
Posts: 8,496
Registered: ‎07-14-2011

Re: Air. Circuit fault and homogeneous mode

The engine computer does not tell you everything about the motor, only certain bits of information and electrical items. The diagnostic software is only one of the many tools used to service and troubleshoot the motor.

 

It sounds like you need to find a factory trained technician who knows how to troubleshoot the motor for you.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Captain
Posts: 638
Registered: ‎08-20-2017

Re: Air. Circuit fault and homogeneous mode

The switch from stratified to homogeneous mode is determined by engine load in order to give the engine more fuel when needed, so what you are seeing is normal. On EVdiag5, the monitor screen would show what air temp the engine is seeing. On the active or occurred faults screen it would indicate if the air temp fault was putting the engine into s.a.f.e. mode and limiting engine speed.
As a tech, I look at EV diag info first, then go to the basics of checking compression, spark, and fuel. Yes, I've made the mistake of spending 30 minutes with the diagnostic software before getting to basics and finding water in fuel or a cylinder with low compression.
Mate
Posts: 2
Registered: ‎06-26-2018

Re: Air. Circuit fault and homogeneous mode

Rickmcd53 I appreciate the response! What is the reason that it would be switching as soon as I get on the throttle or is that when its supposed to do it? Also I was told that a air circuit fault is a internal sensor in my emm....is this correct?
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Captain
Posts: 638
Registered: ‎08-20-2017

Re: Air. Circuit fault and homogeneous mode

A fault code number would be more accurate than the description of an air circuit fault so I'm assuming it is an air temp sensor fault. The air temp sensor is clipped into the air box at the front of the engine.
The barometric pressure sensor is internal in the EMM. The air temp sensor fault shouldn't cause your engine to bog. Switching to homogeneous could depend on how much throttle you were giving it and how quickly and the load on the engine. A restricted exhaust back pressure fitting at the base of the power head could throw off engine load readings also.