[Mark231]

I am new to the forum. Thanks for adding me.
I have a 2007 TRX 400 that is giving me headaches. It is In limp mode.
It's flashing #12 fault code, Shift control Motor and sometimes will blow the 30 amp fuse for the control motor. I have disconnected the motor and put 12V to it so it does turn . Checked plugs for corrosion. Checked battery connections. Now it will not shift with the electric shift and sputters in reverse. I had it running in the shop with the control motor off buy hooked up. I could here it running and even when I shut the key off... the control motor stayed running. I am also getting that dreaded electrical burn smell coming from the CDI box. The side of the box with the 5 wire plug gets dangerously hot and stinks. I am thinking I have a BAD CDI but hate to buy a new one if somthing else is shorted out. I am going to download the manual and go from there. I was wondering if anyone has had the same issues.....
No shift.
Limp mode.
Sometimes blows 30 amp control motor fuse.

Any help would be greatly appreciated.
Thanks
Mark

 

[retro]

Code 12 = ECM motor driver circuit. See page 24-31.

Two more things to check and do... Take the shift control motor apart if you can and see if one of the magnets is broken. Check the brushes and commutator too, for a stuck/worn out brush and/or signs of commutator arcing. Grease the bearing if everything is fine and put it back together. You may need a couple alligator clips to hold the brushes back while assembling it.

Also check the oil temp sensor (resistance check) and the cooling fan circuit for proper operation. If there is a fault with those the CDI may get smokin' hot and fry, due to a nearly shorted control circuit. Check the light blue wire for bared insulation between the sensor and CDI.

https://www.hondaatvforums.net/foru...nual-help/50817-service-manual-downloads.html

Keep us posted on your progress...

 

[Mark231]

Appreciate any and all help.
Thanks.

 

[Mark231]

I now have the manual. See how I make out tomorrow. Right now it's hockey game time. Go Canada Goooooo....

 

[Mark231]

I did the test procedure as per the manual. All tests pass..... pointing towards a BAD ECM.
This morning I had the Control Motor plugged in but not bolted to the engine. I was doing some tests and all of a sudden the control motor started spinning. Even with the ignition off with the key in my hand. Had to unplug the control motor. Took the motor apart. Magnets and armature look good but one of the wires with the female conector going to the brush plate got hot and melted some of the wire coating. Whether that was now or a previous situation. That being said.... Should I replace the CDI and the Control motor. Even with the control motor isolated and unplugged.... my CDI still gets HOT on the 5 wire plug in side . Thanks for the help.
Mark

 

[retro]

Well, it sounds to me like current is flowing when/where it should not be. So you may have some wiring harness issues. Or possibly an ignition switch issue, or both. The CDI might be junk since it gets hot, but what if its not? I'm not gonna make that call... due to the other apparent problems.

It sounds to me like the control motor may be OK, since it runs. But what burnt that brush lead... is there a bad/loose/overheated spade connection there? If so, fix that before putting it back together.

There are too many questions... too many things that need to be fixed before buying anything, me thinks.

I'd be going over the wiring harnesses, fuse sockets and switches at this point. Check the oil temp sensor and fan control circuit too, because if I am not mistaken the fan control unit is integrated into the CDI? So... I question whether the CDI is getting hot because of a cooling system fault, or other fault?

 

[retro]

Is the CDI an OEM Honda part? Or has it been replaced with an aftermarket (china knockoff) unit? Are there any parts on the bike (including switches) that are aftermarket?

 

[Mark231]

You are correct. I am not ready to buy a CDI yet. It is a stock Honda CDI. I noticed today that even with the key off.... The CDI was getting warm. So I unhooked the CDI and battery before I left just for safety sakes.
It may be time to remove the fenders and have a good look at things.
All the test as per the manual passed but somthing is still providing power to the CDI even when the key is off.
I did un plug the fan but not the oil pressure switch as I didn't have time to pull the plow mount off today.

 

[Mark231]

The only switch aftermarket is the winch assey.

 

[retro]

Well there ya go... you've learned quite a bit more about it. So yeah, its time to take the fenders off and have a look-see at the full lengths of each harness. There might be wires rubbed through against the frame or chewed bare by rodents, or melted together... or there might be a waterlogged plug full of green corrosion providing a hot-wire short... or a bad ignition switch. Make sure that light blue oil temp sensor wire is not rubbed bare and grounding somewhere.

Check the fuses to make sure their sockets are clean and tight too. And using a multimeter, check the diode in there for a shorted condition. You're gonna be busy for quite a while... but there is a good chance that it can be fixed without buying any expensive parts.

 

[retro]

Forgot to add... take the ground cables off the motor and frame, clean them up shiny, clean the frame up shiny where they attach and bolt them back down. There are two frame grounds, one under the right side of the rear fender next to the row of harness plugs and another near the CDI.

 

[Mark231]

Thanks for the advice. I appreciate it. Will keep u posted.

 

[ClutchTFS]

I own a 2006 Rancher 400AT. I had the same issue last spring (Around April 2018) I was doing alot of riding in the water and it started doing it intermittenly for a while. I would turn off the bike, turn it back on and everything would work fine for a bit, then it would happen again and I would rinse and repeat.

After a month of that, it completely stopped shifting (stuck in drive in 1st, neutral or reverse, cant shift up from 1st) so I started by replacing the angle sensor as it was the most common fix for people on the forums. After trying that with no luck and still having a code 12 flashing on my display, I decided to read the entire hondamatic section of the manual from start to finish. I learned alot. Firstly (and you may already know this), the shift motor is actually controlled by the ECM ("electronic control module", located under the right rear fairing, near the CDI), not directly by the shift buttons on the handlebar like some people think.

Secondly, when your in "ESP" mode and push either the "up" or "down" shift buttons, there is a signal sent to the ECM which requests it to shift the shift motor according to the button you press. The ECM is there to prevent you from being able to shift when in neutral or reverse (so you dont end up in 3rd or 4th gear when you shift back into drive from neutral, you will always be in 1st). "AUTO" mode is a lot different and too complex to explain here. Essentially it utilizes the angle sensor (sensor for the angle of the motor side swashplate) to determine when to shift and it will then tell the ECM to tell the shift motor to shift.

My point is everything is done through the ECM so if something goes wrong with it, you will usually get a code thrown. In my case, it turned out to be the ECM; the drive motor circuit inside the ecm had shorted out, which I assumed was caused by a frayed wire near the fuse box with overexposure to water from all the water riding.

The easiest way to get past these hondamatic electrical issues without having to spend alot of $$$ (in my opinion) is to hack them. Currently I have a few switches wired up to relays which are powered when the quad is turned on and they allow me to shift the quad directly without needing the ECM (see attached picture). However, there is a way to do this without needing the extra switches. It could be accomplished by wiring each original shift button to a relay connected to the battery, and then having each relay power a circuit to the drive motor. Each circuit would need different current direction (ie. one wired + and - and the other wired - and +), this would allow for full ES shift mode, but AUTO still will not work unless you buy a new ECM.

Hopefully this helps!