04 Rubicon Code 6 (angle sensor) everything tests good by the book??!!

[workandplaymotors 1]

Okay y’all I’ve got a doozy for you smart cookies out there! Long story short my 04 rubicon is throwing a code 6 for an issue relating to the angle sensor. It runs and drives great just won’t shift out of first and sputters/limits rpm in reverse. I have tried new oem angle sensor, new battery, new oem shift motor, swapping ECM and display screen with another rubicon, tested brake switch, shift button switch, gear position switch and reverse switch to be good, tested wires from ecm to angle sensor to be good, tested for shift motor lock, but still am having the issue. Any advise would be very appreciated! I will post more details about my testing/diagnostic process below incase anyone wants to read into it but tried to keep this version short for those who don’t.  

 

 

I found this very clean Rubicon for sale on the classifieds (display was cracked so don’t know true mileage but still has original tires on it) for 2000$ with a snow plow but owner said it wouldn’t shift out of first gear and sputters in reverse. I used to own my own powersports shop/dealer but now I currently am a mechanic at a Honda dealer and just buy and sell used atvs in my spare time so I bought this fourwheeler thinking it would be a easy fix and flip. But boy was I wrong. I’ve spent countless hours trying to diagnose this issue. Luckily I have another 2004 Rubicon that I’ve been able to use for testing and borrowing components. So let’s start with my diagnostic process.

1. Performed visual inspection to check for loose/corroded connections, rubbing wires, loose grounds etc. Didn’t see any visual concerns. Battery tested bad with Honda midtronics tester so I installed a brand new yuasa ytx14-bs. Tested all fuses to be good. Removed and cleaned ground wire junctions with wire wheel.

2. I start in the service manual under the ignition troubleshooting under symptoms with it sputtering in reverse. The book has me test the gear position switch and the reverse switch which test good. I also tested the right hand brake switch since I’ve seen those cause sputtering in reverse before. Tested the up/down shift button switches to be good as well.
3. My display screen had a big crack in it from previous owner and so even though the neutral, reverse, and oil light work, the display doesn’t light up at all so no mph, gear position, odometer and most importantly no ability to retrieve flashing trouble codes. Ran tests in the book to make sure it’s getting power and ground which it was so I think it’s safe to assume the circuit board was damage when the screen got cracked. A new display is discontinued from Honda and couldn’t find a single thing on eBay. 

4. I decided to try swapping the display off the other 04 rubicon even though I was a little worried since it was the gps version and mine is not. But after plugging it in it appears everything is working as it should. Went and test drove machine to make sure the speedometer was working and even though I was only able to ride in 1st gear the mph were registering on the screen indicating the speed sensor is functioning properly.

5. The swapped display was just flashing the drive mode and 2 dashes on the screen were the gear position would normally show indicating it’s in limp mode. Performed code retrieval and got the display to flash code 6 indicating a problem relating to the angle sensor. Tried clearing the code and reinitializing the computer multiple times but it would fail and keep bringing back code 6.

6. Went through service manual and tested wiring going from ecu to angle sensor to be good as well as the angle sensor to be good. Tried swapping the angle sensor with a brand new oem one but that didn’t fix it. Tried the one out of the other rubicon just incase and that one failed too. (Made sure to preload the sensor according to the book) From there the book says to replace the ECM. I swapped the known good ECM from the other rubicon but that still didn’t fix it.

7. When first performing the reinitialization process I could hear the shift motor running like it’s supposed to. It did that the first two times I tried to initialize but then the third time it would just make a knocking sound making me think maybe it was a motor lock issue (which should normally cause a code 5 but I kept only getting code 6.) I removed the shift motor and spun the reduction gear to make sure it wasn’t stuck. I unplugged the shift motor and jumped power and ground to reverse the gear direction backwards to other end till I heard it lock. Then I reinstalled shift motor and tried to do the reinitialization again I was able to do it twice before it reached the end of its travel indicated by the knocking noise.

8. Removed angle sensor to see if maybe the shaft was broken but it was not. Something odd I noticed is in the service manual when it shows how to replace and preload the angle sensor, it shows the shaft being at the 3 and 9 o clock position. But mine was at 12 and 6 o clock. While the angle sensor was removed I unplugged the shift motor and jumped power and ground and watched the angle sensor shaft start at the 12 and 6 o clock position and turn about 1/8th of a turn. Then I reverse polarity and made it turn back another 1/8th of a turn. This made me wonder if maybe there was an internal mechanical issue since the angle sensor shaft was only turning 1/8th of a turn lock to lock. So I removed the angle sensor off the other rubicon and did the same test but it also started at the 12 and 6 o clock position and would only turn 1/8th of a turn as well debunking that theory.

 

So this is where I am stuck at currently. If anyone on here has any bright ideas for me I’m all ears! Luckily working for a Honda dealer I also have access to calling there tech line support so I will try calling them and see if they have any other ideas for me. But if not I may end up having to cut my losses and sell it so I can move on to my other flip projects. Sorry for the long read but I’m trying to document this issue as best as I can in case anyone else has a similar issue in the future. 

[jeepwm69 7,719]

Welcome aboard!  Looks like you've done just about everything I can think of to do.   We've seen Rubicons that wouldn't shift due to a bad TPS, bad wiring, and a host of other things.   I'm sure you know if everything isn't working exactly right on them they drop into limp mode.  Having an extra machine there to test everything is certainly helpful.

 

Given how much work you've put into it at this point, I think I'd try swapping the wiring harness and see if the problem persists. 

 

Also, double check the wiring from ECM to shift motor.   I had a 2014 come to me last year and one of the wires to the shift motor had chaffed in two right in front of the engine.   When I did the initialization process it would spin the shift motor one way, but not the other.  Symptoms were low gear only driving.  

 

 

@Brian Bertram is the Hondamatic guru.   He's a really nice guy, rebuilds Hondamatics (and has now branched out into the Pioneer 1000 DCT's) and I talked Hondamatics on the phone with him for a long time one night.

 

He's not on here a lot, but he posted his email address in this thread.

 

 

[workandplaymotors 1]

@jeepwm69 thanks for the warm welcome, I finally decided to join a couple of the Honda atv forums and Facebook groups not just for help on this issue, but I’m hoping I can also help others and share some of my experience/knowledge as well from working at a Honda dealer that almost solely repairs Honda atvs and sxs. We are a small rural farm town so we see some crazy stuff from our local farmers and ranchers. Me and my coworker have a joke that they are Honda’s unpaid volunteer R&D department. Anyways enough of my blabbering. I did send a email to Brian so thanks for the tip on that. Also I read through your old posts and I  think you may be onto something with the shift motor wiring. That is the same symptom I’m having where I am only hearing the shift motor running one direction and not the other. I talked to Honda Techline today and shared my testing results with him. He said he wants me to go back and test actual resistance measurements for all three wires going from the angle sensor plug back to the ecu. Makes complete sense since I orginally did all my continuity tests with the meter on audible beep sounds (since I was working after hours by myself and my arms couldn’t reach both ends and see the meter screen at the same time).  So even though all my continuity checks tested good indicating I don’t have any broken wires I still need to go back and test ohm values to check for pinched or corroded wires. So I plan on staying late after work tommorow to mess with it some more. I looked up a new wire harness from Honda and looks like they aren’t discontinued yet and my employee cost would be about $260 instead of $465 so if it ends up being a wiring issue and I can’t find it or repair it easily I may just end up replacing the harness but ideally I’d solder it or splice in a new wire.

[jeepwm69 7,719]

13 hours ago, workandplaymotors said:

@jeepwm69 thanks for the warm welcome, I finally decided to join a couple of the Honda atv forums and Facebook groups not just for help on this issue, but I’m hoping I can also help others and share some of my experience/knowledge as well from working at a Honda dealer that almost solely repairs Honda atvs and sxs. We are a small rural farm town so we see some crazy stuff from our local farmers and ranchers. Me and my coworker have a joke that they are Honda’s unpaid volunteer R&D department. Anyways enough of my blabbering. I did send a email to Brian so thanks for the tip on that. Also I read through your old posts and I  think you may be onto something with the shift motor wiring. That is the same symptom I’m having where I am only hearing the shift motor running one direction and not the other. I talked to Honda Techline today and shared my testing results with him. He said he wants me to go back and test actual resistance measurements for all three wires going from the angle sensor plug back to the ecu. Makes complete sense since I orginally did all my continuity tests with the meter on audible beep sounds (since I was working after hours by myself and my arms couldn’t reach both ends and see the meter screen at the same time).  So even though all my continuity checks tested good indicating I don’t have any broken wires I still need to go back and test ohm values to check for pinched or corroded wires. So I plan on staying late after work tommorow to mess with it some more. I looked up a new wire harness from Honda and looks like they aren’t discontinued yet and my employee cost would be about $260 instead of $465 so if it ends up being a wiring issue and I can’t find it or repair it easily I may just end up replacing the harness but ideally I’d solder it or splice in a new wire.

 

Brian was the one who asked me if I could hear the motor going both directions, and said he'd had the same problem on one, and when I looked, sure enough, that's what it was.  Made my fix easy.

 

What part of the country are you in?   If you don't want to be specific, totally understandable since you're in the biz.

 

While you get a discount on new Honda parts, you might look into powersportsnation.com.   They stand behind what they sell, and have an 18% off sale coming up June 23-29.   You have to buy 3 or more parts to get the discount, but normally if I need something bigger I'll order a couple of wheel center caps or an extra starter solenoid ($5-6 parts) to get to the "three parts" threshold which is more than offset by the discount on the big part.  They aren't nearly as cheap as they used to be, but they have been excellent about replacing or refunding any used part I've bought from them that I wasn't happy with.

 

https://www.powersportsnation.com/honda-rubicon-500-fa-03-wiring-harness-32100-hn2-000-39685.html

 

They're parting an 04 FGA now, but no wiring harness listed yet.   The GPS on these Hondas is garbage anyhow, so to save $180 I'd just delete the GPS/ leave it unplugged.

 

Glad to have another dealership guy here.   Does your dealership work on older machines still?  Most around here don't want to mess with anything over about 10 years old.

 

@toodeep was at a dealership for a long time back when he was a mod on hondaforeman dot com (before vertical scope bought and ruined the forum) but he's farming now, but still weighs in on things here on the "new" forum.   Dealership experience is great, especially with the resources yall have available.   Then you have the shadetree guys who see stuff and figure out things that Honda won't tell you, like 420 discs and a 400AT front diff on a 350 Rancher etc.

 

Stick around!   Lot of good guys here who like to talk and wrench on Hondas.

 

[workandplaymotors 1]

Sorry @jeepwm69 I guess my reply to your last comment didn’t go through. I am in central Utah and since we are a smaller Honda shop we don’t always have the luxury of being picky about what we work on so most of what we repair is late 90s-late 2010s Utility atvs and sxs. I used to buy a lot from powersports nation when I was running my own business but I mostly specialized in Polaris’s so I’ve never bought Honda parts from them. I took your advice and found some stuff on their website I was looking for but unfortunately no display for mine yet. But I do have good news!! I was able to fix the angle sensor code issue. Turned out to be two of the wires going from the angle sensor to the ecm had just barely chafed somewhere along the wiring harness causing continuity between the two wires throwing off the resistance signal going to the computer. I tried to visually trace the harness to find where the chaffing could have happened but no luck. I’ve already sunk quite a bit of time into this flip so rather then buy a whole new wiring harness and tearing the machine apart to replace it I just decided to cut the two wires and splice in my own 2 wires between the ecm and angle sensor. Don’t worry I didn’t just do a quick hack job to get it out of there. I used quality solder shrink connectors and used high quality wiring with double insulation around the wires. I also used bmw grade fiber wrap tape around the connectors to help with heat and abrasion resistance and ran the wires right along the factory harness incase anyone has to do any repairs or wiring to it in the future. It was already super clean so it shined up pretty easy with some sc1 and I got it listed for sale. I ran NADA/JD power book value on it and it came back at $6695 for excellent condition which I would say this one fits the bill so I decided to start at $5500 with the plow and trailer. Hopefully that’s a fair price and I can have it sold soon so I can move on to my poopoolaris general and ranger flips. 

[jeepwm69 7,719]

Ah, so it was the same ! thing that was wrong with that 2014 I fixed!   Once again, Brian's "oh, if it's doing that, then this is probably what's wrong" comes through!

 

Glad you got it fixed!

 

I saw that thing listed in FB and kinda scoffed at the price until I looked at the pics.  Thing looks like it just rolled off the showroom floor.

 

Any idea what's wrong with the meter?  Thing doesn't look like it would have more than a couple hundred miles on it!

 

 

[jeepwm69 7,719]

You might bounce what's going on with your meter with @AKATV.   If a meter isn't full of water he can usually fix them, and might be able to tell you some simple testing you can do to see if your problem is something simple.

[shadetree 5,969]

19 hours ago, workandplaymotors said:

Sorry @jeepwm69 I guess my reply to your last comment didn’t go through. I am in central Utah and since we are a smaller Honda shop we don’t always have the luxury of being picky about what we work on so most of what we repair is late 90s-late 2010s Utility atvs and sxs. I used to buy a lot from powersports nation when I was running my own business but I mostly specialized in Polaris’s so I’ve never bought Honda parts from them. I took your advice and found some stuff on their website I was looking for but unfortunately no display for mine yet. But I do have good news!! I was able to fix the angle sensor code issue. Turned out to be two of the wires going from the angle sensor to the ecm had just barely chafed somewhere along the wiring harness causing continuity between the two wires throwing off the resistance signal going to the computer. I tried to visually trace the harness to find where the chaffing could have happened but no luck. I’ve already sunk quite a bit of time into this flip so rather then buy a whole new wiring harness and tearing the machine apart to replace it I just decided to cut the two wires and splice in my own 2 wires between the ecm and angle sensor. Don’t worry I didn’t just do a quick hack job to get it out of there. I used quality solder shrink connectors and used high quality wiring with double insulation around the wires. I also used bmw grade fiber wrap tape around the connectors to help with heat and abrasion resistance and ran the wires right along the factory harness incase anyone has to do any repairs or wiring to it in the future. It was already super clean so it shined up pretty easy with some sc1 and I got it listed for sale. I ran NADA/JD power book value on it and it came back at $6695 for excellent condition which I would say this one fits the bill so I decided to start at $5500 with the plow and trailer. Hopefully that’s a fair price and I can have it sold soon so I can move on to my poopoolaris general and ranger flips. 

pssttt..we don't use the '' P '' word around here !...rofl.