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testing an ECU ?????? Honda Mechanic!!

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  #11  
Old 05-03-2008 | 08:49 PM
HondaMechanic's Avatar
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Default testing an ECU ?????? Honda Mechanic!!

We clean the starters up on bikes that shift slow (lazy shift control motors) .. Honda says the ESP should shift gears in 35 milliseconds so the ECU supplies power to the shift control motor for 70 milliseconds , but a lazy shift control motor may or may not complete the gear change in the allowed time ..

This is cleaning a shift motor ..

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these are the tools needed to clean the shift control motor ..

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Remove the allen bolts and remove the motor case (reach under the motor and hold the
spline teeth of the stator or it will come out when you remove the motor case ..



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The magnets are epoxied onto the case make sure the glue hasn't seperated
and the magnets are in good shape ..

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Remove the armature and check the commutator bars (as you see these were bad
before I cleaned them up ..



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Check the springs ...


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Install the springs and brushes back into the track they run on and
install the armature it's easier if there are 2 people for this step
1 to hold the brushes back , 1 to install the armature ..



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Use a small screwdriver and apply a little grease around the rubber seal
and a small spot of grease on the bushing inside the motor case ..
(do a better job of greasing than I did) ..Then reach under and hold the
armature while installing the motor case (if you don't hold the armature
the magnets will pull it out of the brushes) install the screws ...



 
  #12  
Old 06-03-2014 | 01:14 PM
gageadam1990's Avatar
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Originally Posted by Gimpster
My personel quad is a 2001 450 foreman. When I bought it my display did the same thing and I chased the problem over and over. I had tested my shift control motor with 12 volts also and it spun fine. I believe these motors operate on 5 to 7 volts. I also threw an ECm at it and it did not cure the problem. Gear position switch also Cluby on here kept telling me it was the shift control motor and I would not believe him because I could get it to spin off of 12 volts both ways. The test in the servive manual is only to see if power is going to the speed sensor and a slight voltage rise when the wheels are turned. The only way to tell if it is working is to watch for any glitch in the MPH display. Honda's test will not pick up a high end glitch in a speed sensor A lot of times it takes hitting the rev limiter to set it off as being bad. This system has no way to get codes as it is pre 2002. It will only shut down the system is a problem is noted. What convinced me is when I pulled the shift control motor apart, cleaned it and reinstalled. My display began to read all the gear positions, for about 15 minutes of riding then went into shutdown again. I ordered a new shift motor, installed it and have not looked back since. Display and shifting work and read like they are supposed to.
Here is a good one to compare. WHen you look for a voltage draw on a car, bike, etc... you disconnect the negative battery cable, clip one end of a test light to the unhooked battery cable and the test light probr to the negative terminal. If you have a draw (even the slightest) the bulb will glow. You cannot test for a draw across the posative and negetive terminals of the battery and get these results.
Everyone on here says to check a shift control motor by connecting a positive and negative cable to it and check if it turns in each direction. I think of this as a quick test, but you get the same results as looking for a draw on a battery as I said above with your test light across the posative and negative battery terminals. The light will light as the motor will run when connected to a battery. To check a shift motor for a draw you have to connect a 2 to 4 watt bulb inline at hthe shift control motor's connector. One bulb for each of the 2 terminals. If they glow you have a draw in the motor. Same as doing a draw test across the disconnected negative battery terminals The ECM picks up this draw and shuts the shift system down. This is the BEST test for a shift contorl motor, plain and simple.
Your Honda dealer is right. They would need your unit to check the ECM. To check the ECM you have to install a different ECM in the unit. There is no tests available across each and every terminal of the ECM, that exist. SInce your unit was under water, It needs to be treated as what Honda terms a flooded shift control motor. In the long run the real only cure is to replace it.
If you trace the 1st gear readout back through the wire harness, it ends up getting a ground through the shift angle sensor. I believe the ECM shuts this system down when it reads a draw within the shift control motor. It is just one way I have become aquainted with reading a meter on a pre 2002 unit when they have a shift motor issue. A diagnosis step you could say as I have had to replace the motor in every unit that has displayed the meter functioning as you have described.

----- Gimpster -----
My 2001 honda foreman is pretty similar my 2nd 3rd and 4th read (--) on the dash and my electric shift Is dead nothing no life from it up or down and I hit my shift motor with 12v and bam it turns over and shifted my quad but nothing at all I was going to buy an angle sensor but took it out and put a meter on it and test it with resistance in ohms from 0.002 to 6.00 ohms it read but then it jumped to 45.0 ohms the exact other way so how's that? And I bought my bike used full of trash grass ext... so I assumed my bike has been in water and maybe your answer is correct damage to the shift motor can be the cause of my electric shift system to go dead? Oh something to mention I tested the wires going to the motor to see if I was getting anything when I hit the shift button I was getting 2.5 volts constantly and no change when I was hitting the button
 
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