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Discussion Starter · #1 ·
I'm working on my brother in law's 2005 Honda Rancher TRX350FE. He said sometimes it would get stuck in gear but if he shut it off and went back the next day a lot of times it would go back to neutral and then work again. Gradually got worse until I picked it up to take a look.

When I first picked it up it had a #3 code for the angle sensor so I bought a replacement and put it on...still wouldn't shift. I noticed the old sensor would only turn so far before stopping & the new one would turn completely around...I thought I'd maybe got a bad one or broken it so I tried another one & still won't do anything. When I push the shift buttons it doesn't do anything at all.

I had a friend take a look at it...we put a wrench on the manual shifter shaft and it goes through the gears if you rock it a bit...should it have to be rocked? I thought maybe I should be able to shift it without rocking it (when turned off) but he said it felt normal.

So...I went back through the troubleshooting steps in the manual I ordered. If I shift it manually with the engine off & key on the position indicator shows the correct gears. I can't find any connections that look bad. I disconnected the ECU connector & I have continuity when pushing the shift buttons so they should be fine. The next step in the manual was to replace the ECU...so I did that & still no change.

I manually shifted into 1st and the button will shift it back to N...but only once. After that it won't do a thing. I pulled the shift motor plug apart and I'm not getting any power to it when I push the shift buttons.

I've seen the threads about the part that breaks in the front of the trans that you have to basically pull the engine to get to. Is that my next step? If something was binding should I hear it trying to shift?
 

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Actually there a lot of possibilities. You have provided a wonderful description and I will provide what help I can without actually having the machine here to touch and feel.

Since the transmission will shift manually (and I presume drive in all gears) then the transmission is eliminated as a problem. Yes, rocking to shift is normal. Actually there is little chance of shifting either manually or electrically without either the engine running or the wheels turning. Being a 4WD, you should get all 4 wheels off the ground to troubleshoot this problem.

Unplug the shift motor from the wiring harness (orange and green/blue wire) - with the engine running, check for voltage between the two wires when pushing the shift buttons. Voltage will be positive when pushing one button and negative when pushing the other button. If no voltage, check the shift motor fuse (30 amp marked MOTOR in the fuse box). A bad connection at the fuse could have caused intermittent shifting leading up to the current status of this problem. If voltage is present at the connector, remove the shift motor for testing.

With the shift motor removed from the engine, connect the motor plug to the wiring harness. With the engine running (in neutral) press the shift switches. The motor should turn clockwise when pressing one switch and CCW when pressing the other switch. If the shift motor checks good, remove the cover the shift motor is bolted to. There are reduction gears inside the cover. I have seen moisture combine with the lubricant for these gears and turn to "glue" or the bearings for the gear shafts go bad and prevent the mechanism from working.

Let me know what you figure out and then we can progress from there.

Kudos on buying a manual - it cannot cover every possible scenario, but it will make the process of dis-assembly and proper assembly much easier.
 

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Discussion Starter · #3 · (Edited)
Let me know what you figure out and then we can progress from there.
When the shifter did happen to work it would operate normally in all of the gears.

The fuses are all good, connections look good, and I'm getting battery voltage to the 30A fuse.

There is no voltage at the shift motor connector.

Working through the shop manual troubleshooting procedures I have confirmed that there IS continuity between the 22P/Brown connector at the ECU Black/Red wire & White/Blue of the up switch as well as continuity between the Black/Red & White/Yellow of the down switch. So the gear shift buttons & wiring should be good back to the ECU.

I've also confirmed continuity between the Black/Red, Yellow/Blue, and Blue/Green wires between the ECU 22P/Brown connector and the shift angle sensor connector.

The ECU and shift angle sensor are both new.

So....I started going through the troubleshooting tests page by page & ignoring what code they were supposedly for. Here's what I found:

On page 22-11 it says to turn the ignition switch OFF and disconnect the ECU connector test harness. "Measure the resistance between the Yellow/Blue and Blue/Green terminals of the wire harness side of the ECU connector while shifting through all of the gears." Resistance should be 0-5 Ohms. I'm getting 28 Ohms. According to the troubleshooting chart I have a faulty angle sensor...although I've replaced it...twice....
 

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Are you certain you have the right manual? You should have Honda service manual number 61HN452. The number is on the back cover of the book.

To do the test you are describing, you need a "test wiring harness" Honda part number 07YMZ-0010100 which I doubt you can get or is no longer available. Anyway, using the manual, start at the beginning and do each test step by step. When you get to step 6 (page 22-11) where you are supposed to install the "test wiring harness", yon need to do what is reffered to "back probing" the connector to measure the voltage. Without disconnecting the ECU connector, use a straight pin with some dielectric grease and slide the pin between the wire insulation and the rubber seal to contact the connector pin and read the voltage. Continue on not skipping any steps and read carefully - some steps require disconnection and some require "back probing". Good luck.
 

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Discussion Starter · #5 ·
I have a manual download...doesn't include the back cover. The front cover says 2004-2006 Honda TRX350TE/TM/FE/FM Fourtrax Rancher. So far everything in the manual has matched up to what is on the Rancher I'm working on.

Following the specific trouble shooting flow charts for my problem just kept leading me back to "Replaced ECU & troubleshot again" or "Faulty angle sensor" so I started at the first page of the troubleshooting page and started checking everything.

Yes the test says I need a "test wiring harness" but once I looked at the picture and the wiring diagram I realized it was basically just a Y so I back probed the connectors and that is when I got this:

On page 22-11 it says to turn the ignition switch OFF and disconnect the ECU connector test harness. "Measure the resistance between the Yellow/Blue and Blue/Green terminals of the wire harness side of the ECU connector while shifting through all of the gears." Resistance should be 0-5 Ohms. I'm getting 28 Ohms. According to the troubleshooting chart I have a faulty angle sensor...although I've replaced it...twice....
So...I'm back to thinking I have an internal problem. It is acting like something mechanical is either not allowing the angle sensor to turn far enough...or allowing it to turn too far.
 

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I have the proper manual - the first thing on page 22-11 is paragraph 6.

Sometimes you have to perform tests that are not in the book

As in my first post: With the shift motor removed from the engine, connect the motor plug to the wiring harness. With the engine running (in neutral) press the shift switches. The motor should turn clockwise when pressing one switch and CCW when pressing the other switch. If the shift motor checks good, remove the cover the shift motor is bolted to. There are reduction gears inside the cover. I have seen moisture combine with the lubricant for these gears and turn to "glue" or the bearings for the gear shafts go bad and prevent the mechanism from working.

I'm guessing the motor can't turn the gears which in turn operates the shifter.
 

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Discussion Starter · #7 ·
I have the proper manual - the first thing on page 22-11 is paragraph 6.
My page 22-11 also starts with paragraph 6 "Angle Sensor Input Voltage Inspection".


Sometimes you have to perform tests that are not in the book

As in my first post: With the shift motor removed from the engine, connect the motor plug to the wiring harness. With the engine running (in neutral) press the shift switches. The motor should turn clockwise when pressing one switch and CCW when pressing the other switch. If the shift motor checks good, remove the cover the shift motor is bolted to. There are reduction gears inside the cover. I have seen moisture combine with the lubricant for these gears and turn to "glue" or the bearings for the gear shafts go bad and prevent the mechanism from working.

I'm guessing the motor can't turn the gears which in turn operates the shifter.
I'd posted earlier that I currently have the shift motor removed & it does not turn when I push the shift buttons. But...I never get any voltage at the shift motor plug to make it turn.
 

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OK - back to the beginning - when you push and hold both the up shift and down shift buttons and turn the key on; then before the "N" indicator appears and you release and press both buttons and hold them for more than 3 seconds, what codes are indicated? More than one? How many and what are they?
 

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Discussion Starter · #9 ·
OK - back to the beginning - when you push and hold both the up shift and down shift buttons and turn the key on; then before the "N" indicator appears and you release and press both buttons and hold them for more than 3 seconds, what codes are indicated? More than one? How many and what are they?
Right now I can't get it to show any codes. When I first started on it I was getting a code 3. If I cleared the code, started the Rancher, then tried to shift the code 3 would reappear. After replacing the ECM it hasn't flashed a code for me.
 

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Now; we will presume there are no fault codes being generated. The machine thinks all is working well. Does the dash indicate the gear position properly when shifted manually?

If it does the problem is electrical - try unplugging and plugging in all the wiring harness connectors. It would appear you have lost a voltage signal either through a bad connection or a faulty wire. When you unplug a connector and before you plug it back together, look at the pins and sockets to see if corrosion is visible or if a pin or socket appears to be pushed back into the connector further than the rest of them.

You might have to use a meter and chase the voltage from point to point.
 

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Discussion Starter · #11 ·
Now; we will presume there are no fault codes being generated. The machine thinks all is working well. Does the dash indicate the gear position properly when shifted manually?

If it does the problem is electrical - try unplugging and plugging in all the wiring harness connectors. It would appear you have lost a voltage signal either through a bad connection or a faulty wire. When you unplug a connector and before you plug it back together, look at the pins and sockets to see if corrosion is visible or if a pin or socket appears to be pushed back into the connector further than the rest of them.

You might have to use a meter and chase the voltage from point to point.
I had the ECM plug loose. With everything back together I get code 3. I can manually shift through all of the gears fine and the gear position indicator shows the proper gear as I'm shifting.

I printed off the wiring diagram for the ES system and went through every wire and every plug and they are all good. The only thing I can find is on page 22-16 they say to check the resistance at the ECM plug for the wires coming from the angle sensor and they should be 4-6K. I'm not getting anywhere close to that with either of my new angle sensors...but the old one is in that range. The new sensors are both under 1K ohms. In addition if I remove the sensors and hook my meter directly do them their resistance does not change if I manually turn them. I think I have two brand new...but defective...angle sensors.
 

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I just re-read all the posts to try to get a fresh picture of the procedures up to this point.

I didn't see that you tested the motor by simply connecting it to 12vdc - it should run one way and reversing the voltage make it run the other way - if you did that and it checked out, then back to the angle sensors.

First - did you check continuity of the black/red, yellow/blue and blue/green wires between the ECU connector and the angle sensor connector? Also, have you checked continuity of the motor wires (orange and green blue) between the ECU and the motor connector? If yes, then.......

There is 3 pins on the angle sensor - the two outer pins should have continuity between them and measure a constant resistance (perhaps 8 to 10 ohms). between the center pin and each outer pin the ohms will change as you turn the position sensor increasing in one direction and decreasing in the other direction. It will be the opposite from the center pin to one outer pin as to the other outer pin.

Last thing I can think of is: does the angle sensor shaft on the engine turn? This can be tested; with the angle sensor removed, apply 12vdc to the shift motor terminals and watch the shaft that operates the sensor - it should turn as the motor runs. Reverse the polarity and it should turn the opposite direction.

Somewhere along here you should find the problem. Beyond this point, I would have to get my hands on it. You might have to end up taking it to a dealer.
 

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Discussion Starter · #13 ·
I just re-read all the posts to try to get a fresh picture of the procedures up to this point.
Thank you

I didn't see that you tested the motor by simply connecting it to 12vdc - it should run one way and reversing the voltage make it run the other way - if you did that and it checked out, then back to the angle sensors.
I hadn't because I'd confirmed I wasn't getting any voltage at the shift motor plug when pushing the shift buttons. But I just hooked it up direct to 12V and it spins great in both directions.

First - did you check continuity of the black/red, yellow/blue and blue/green wires between the ECU connector and the angle sensor connector? Also, have you checked continuity of the motor wires (orange and green blue) between the ECU and the motor connector? If yes, then.......
Yes. I've checked continuity between shift buttons to ECU, angle sensor to ECU, and shift motor wires to ECU.

There is 3 pins on the angle sensor - the two outer pins should have continuity between them and measure a constant resistance (perhaps 8 to 10 ohms). between the center pin and each outer pin the ohms will change as you turn the position sensor increasing in one direction and decreasing in the other direction. It will be the opposite from the center pin to one outer pin as to the other outer pin.
I'll label the 3 sensors I have A, B, & C with senor A being the original and B/C the two new ones.

A - outer/outer is 4.32k ohm.
B - outer/outer is 11.22 ohms.
C - outer/outer is 8.59 ohms.

Readings taken with sensor laying flat & engine side facing up. Connected to center & right pins:
A - 300-400 ohms turned clockwise against the stop & 4.94k ohm turned counter clockwise against the stop.
B - about 25 ohms regardless of position
C - about 28 ohms regardless of position

Readings taken with sensor laying flat & engine side facing up. Connected to center & left pins:
A - 4.72k ohms turned clockwise against the stop & 500-600 ohms turned counter clockwise against the stop.
B - about 12 ohms regardless of position
C - about 10 ohms regardless of position

Last thing I can think of is: does the angle sensor shaft on the engine turn? This can be tested; with the angle sensor removed, apply 12vdc to the shift motor terminals and watch the shaft that operates the sensor - it should turn as the motor runs. Reverse the polarity and it should turn the opposite direction.
I'm out of time this morning...I can check that later.

Somewhere along here you should find the problem. Beyond this point, I would have to get my hands on it. You might have to end up taking it to a dealer.
I have very little faith in the dealers but my brother in law really needs it back & I'm tired of writing off hours going in circles. He is picking it up Saturday fixed or not. :confused:
 

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Based on the readings I would say sensor A is the good one, but just having the sensor plugged in when not attached to the engine and in the center position, the shift motor should run when the button is pushed. The angle sensor tells the ECU when the shift is complete and to stop running. Sorry I can't be of more help.
 

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Discussion Starter · #15 ·
I gave up after replacing the ECU, trying several angle sensors, & testing all of the wires. I even took the front cover off to check out the gears. The local Honda dealer has had it for quite a while now. At first they replaced the shift motor because they were told by Honda that the specs in the manual were wrong. It passed the manual test but not the test Honda sent them...but that didn't fix it. They have now ordered every single part of the shift system & are going to replace things one by one until they figure it out...then credit me back the parts they didn't need. What a mess.
 

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Yes, it happens - problems that are not in the book. Sometimes it takes a mechanic with a degree in electronics to figure it out.

I would say the Honda dealer is doing their best under the circumstances. Replacing all the parts to find out which one is bad is a crude way of going about it, but usually effective, unless the problem ends up being in the wiring, then all the new parts won't fix it unless they replace the wiring harness also.

Hope it works out.
 

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Discussion Starter · #17 ·
Yes, it happens - problems that are not in the book. Sometimes it takes a mechanic with a degree in electronics to figure it out.

I would say the Honda dealer is doing their best under the circumstances. Replacing all the parts to find out which one is bad is a crude way of going about it, but usually effective, unless the problem ends up being in the wiring, then all the new parts won't fix it unless they replace the wiring harness also.

Hope it works out.
What I kept running into was a lack of technical info. Ohming the wires is easy enough but I needed to know what output the ECU was supposed to provide & when. They told me the shift switch wasn't testable...but I had an ohm meter hooked up and the buttons made/broke continuity whenever I pressed them. At this point I'm thinking wiring harness but we'll see.
 

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Discussion Starter · #18 ·
Dealer eventually replaced EVERY switch/sensor and that didn't fix it. They took most of it back off & installed a new wiring harness...then gave it back to me with no engine oil.

So:
New angle sensor...they said the ones I'd ordered were wrong = error in catalog I guess?
New shift motor...Honda said the test specs in the manual were wrong
New wiring harness....dealer & I both ohmed the wires and couldn't find anything wrong. Not sure where the problem was but it was there.
 

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Most problems are simple, but then every once in awhile, what can't possibly happen does, then it becomes a nightmare. Sometimes it simply is beyond the help available in a forum and Honda dealers have access to Honda Factory Technical Service. That is where they find out the manuals are incorrect.
 
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