2010 RXV Problem

[jon21588]

What I know:

Cart can be rolled in tow/neutral

I'm 99.99% sure the emergency brake is working correctly.
I have taken the brake on and off at least 5 times. I have thoroughly cleaned it.
The brake is getting the same voltage as tow/neutral as it is in run/forward and pushing the accelerator pedal. It has a very audible click when engaging and disengaging.

When pushing the accelerator pedal, the motor shakes and barely moves the tires. When you push the cart to help it, it's sort of jerky. I thought maybe the brake was sticking so I took the brake most of the way off while it was in drive and it does the same thing.

I have cleaned and checked throttle and brake sensors. They are working fine.

I just ordered a new encoder bearing even though it ohms out according to the troubleshooting guide.

I wanted to check to see if anyone had any thoughts as to whether that may be the problem. I don't have a dealer anywhere near me that has the handheld to check codes.

Thanks in advance.

[jon21588]

I want to add that it had an intermittent problem before it started this new issue.

It would randomly not run. When put in tow/neutral it and pushed, it would eventually run again. I charged batteries, took brake off and cleaned, reinstalled and loosened bolts and seemed to work fine. Once it sat for more than a few minutes, it would do the same thing. Eventually I could get it running again but it would do the same thing when it sits for a prolonged period.

One more thing:
It will not move without a little help. I see others saying theirs goes 1mph. With the rear end off the ground, the tires do spin very slowly in sort of a start/stop motion.

[canterburya]

Based on my experience, this is a classic symptom of a bad bearing encoder. It is a pretty straightforward process to replace it. Plenty of info on the forum regarding replacement. You do have to remove the motor from the cart. The wires that go from the motor to the controller come out with the motor. There are more experienced people on this forum that might chime in. I think that you are on the right track replacing the bearing encoder.

[jon21588]

I just did this test on the encoder wires.

Positive to red/negative to white:
.115 stationary
2.228 max

Positive to red/negative to blue:
.115 stationary
2.667 max

Guide says to replace motor? I hope not!

[canterburya]

Do this test. Check pins 3 and 4 on the controller. Put the positive probe on the orange wire PIN 3 and the negative lead on PIN 4 black wire. You should see 5V or close to it.

[jon21588]

I got 5v from that test last night, but I'll check again.

[jon21588]

This cart is about to kill me...

So I was just testing the voltage from the encoder in basically every combo possible.

A couple things I noticed:

The voltage kind of depended on where the tires came to rest. Sometimes it read .12v and others it read 4.99 volts. I tried to run it with the wheels offf the ground in reverse/forward, with the brake on and off, with the starting voltage at .12 and at 4.99. Just every possible way. Then the brake started not disengaging with the throttle.

I tried a few different things and all of a sudden something changed. When I toggled to run and turned key to forward:

Solenoid clicks
Low volume buzzer sounds
And a very small jolt/rubbing sound(twist test)

I immediately installed the brake back on the motor and after getting it aligned and everything, THE THING FINALLY WORKS!

So I cycle key switch a few times, cycle run tow, forward/reverse and it still works.

The bad news:
When key is in reverse, after POST, I press the throttle and it doesn't move and the reverse buzzer sounds interrupted and about half volume. After backing off throttle and pushing it again, it runs normally in reverse. Going from off to forward then to reverse, the buzzer interruption doesn't happen and cart performs normally.

Anyone have a clue what this could be?

[bdserv]

Originally Posted by jon21588

The voltage kind of depended on where the tires came to rest. Sometimes it read .12v and others it read 4.99 volts.

That is what is supposed to happen. The encoder produces a binary output where 0 volts is "0" and 5 volts is "1" and there is nothing in between.

When you rotate the wheels slowly you can see the output switch between 0 volts and 5 volts. When you spin the wheels fast your meter is reading the average voltage of the rectangular waveform that is produced by the rapid switching between 0 volts and 5 volts.

[jon21588]

Am I reading this right? I should have continuity between pin 10 and 13 with the harness unplugged from controller?

[jon21588]

I’ve tested pretty much everything in the troubleshooting guide.

I got a new bearing encoder in this morning, but was hesitant to install it until I checked a few more things out. I think I’ll install it tomorrow and pray it works.

These were done with rear axle off the ground:

Brake installed
tow/key in neutral - back wheels spin freely
run/key in neutral - after pushing throttle to release brake, back wheels have resistance and do not move smoothly

When brake is off the cart, the same things occur. I did test with the key off when the brake was off and it rolled freely. It is locked when the brake is installed.

Does this make sense? I’m hoping someone will confirm or disprove my thinking here before I yank the motor out.