[Jensonstewart]

Hi everybody I’m new here, I am from Uk I love reading your discussions on here I think there brilliant. Right my first post. I have got a 2015 Honda trx 500 fm1e the problem I have is it is stuck in 4wd tried a few things push the disengage button and switch off and on etc. Nothing seems to work and also when I try to put front differential locks on the light just flashes I think it’s supposed to stay on when it’s engaged. Do you think I should buy a new switch assy or is there a way I can test if it’s working or not? I’m not the best mechanic but will have a go at anything. Just so that you know I have checked for any moisture or corrosion on all of my plugs & diodes under the seat and all look like new. And have today done full oil change engine & both diffs

Thank you so much for reading this post and thank you very much in advance for my miracle answer ?

 

[retro]

Check the simple electrical stuff first... do you have a copy of the service manual yet?

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

Welcome to the forums!

 

[fishfiles]

Welcome Jenson' , it could be worst , you could be stuck in 2wd !

 

[Jensonstewart]

No don’t have a copy of the manual yet. thank you very much. And yes could be worse could be stuck in 2wd. My lights don’t work either wether that’s anything to do with it or not I don’t know? After I bought the quad I found out that it had sunk (in a lake) a few month back and had to have the stem seals replaced. It runs perfect and has got so much power. Just need to get it working. What would you recommend trying when you say try the basic stuff first? Is there a way to test relays? Or can I take the actuator apart on the front diff?

 

[retro]

A quick test: Unplug the front diff clutch and test ride it. If it is still locked in 4wd the front diff clutch is bad... either a broken return spring, jammed rollers, or debris stuck behind the engagement sleeve. Keep us posted...

 

[Jensonstewart]

Sorry for my ignorance ☹ how do I unplug that plug? where is it? what does it look like?

 

[retro]

I just went back and looked at this again... I gave you bad info pertaining to the old system.

This one uses a motor to actuate and has twin pull-back relays... along with several other u$ele$$ electrical trap$. You'll have to pull DTC codes, then read and follow the diagnostic steps in the service manual (linked above) to find the fault. Keep us posted...

 

[retro]

When you browse for the manual, find the one that covers all models from 2004 through 2016. Your system is well covered in that manual.

 

[fishfiles]

I don't have a 500 , but got a 450 , I was just looking at the front diff of a 500 and it is similar ------ on the 450 with no power to the diff clutch then it is in 2wd ------ so I would think you either have power all the time to 4 wd for some reason , or something is stuck inside the diff ---- that's just a wild guess

 

[Jensonstewart]

Unplugged front diff and drive it back and forth etc still stuck in 4th gear. Photo attached to show what I unplugged

 

[fishfiles]

So I would think something has to be stuck inside the diff. How's the oil look.

 

[Jensonstewart]

I changed all the oil. It was smoothe but dark. I have just pulled this cover off (see pic) and turned the cog to push the diff in and out the display changed on the dash from 4wd to 2 and from 2 to 4 also tried pushing the 4wd button and keeping my finger on the little motor but it didn’t move nor make a noise.

 

[retro]

Ya, the newest system is way different than the old... it uses a motor to operate diff-lock and traction-lock. Problem is, there are a gazillion sensors and relays and switches and ECM that control that little actuator motor. Spending a day with the service manual, pulling codes and probing with a multimeter is the only way you're gonna learn what is wrong with it. You can test that motor using jumpers to see if it runs... make sure nothing is plugged into it if you do. Electronics are fragile, sensitive and expensive on those... be careful. Use the manual... not assumptions. Let us know what you find.

 

[retro]

Also, the bike might need to be running, in gear, before the diff-lock will engage. I don't know much about them.

 

[Jensonstewart]

When you say pulling codes what exactly do you mean please?

 

[retro]

Codes = Diagnostic Trouble Code or DTC. The ECM does a self-test every time the ignition is turned on. If it detects a fault it stores a DTC in its memory and sometimes flashes the DTC on the display. While the bike is being driven if there is any kind of fault the ECM does the same... it can store DTCs in memory and/or flash the warning on the display. There is generally a fail-safe mode mapped into the ECM... sometimes called limp-home mode... which allows the driver to get the bike home unless there is a catastrophic failure of a major component. Then you're walking home...

The '04-'16 service manual covers this system very well. As you'll see when you read the manual, about 70% of the front final drive section is DTC troubleshooting and testing steps.

 

[Jensonstewart]

I can only read the manual on my iPhone 4s ? it is painstakingly slow I has took me about 2 hours to get to the self diagnosing part. I need a laptop or to buy a paper manual. Anyway I have done a video of the error code it brings up after shorting the wires to bring up old faults. If anyone could give any advice on what the code means I would much appreciate it. Thank you very much. Can’t uoload the video but I will try explain:

4wd & diff - 1 long flash followed by 1 short

Ecu light
7 long
1 long 1 short
2 long 3 short

 

[retro]

Ya, phones are very poor tools to be stuck using the Internet with... Lets see if screenshots help ya..?

Got a question tho... was the display flashing while the ignition was on indicating a fault, or did you have to pull all of those codes?

Pic dumps follow...

 

[retro]

More pic dumping...

 

[retro]

And some more...