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Discussion Starter · #1 ·
Good evening. Still struggling with corn harvest here in the Great Lakes Basin. Ah the joy of being downwind when cold air passes over warm water... Just enough snow to pooch corn harvest until it melts off..

Our MY '10 575R with AutoPilot running on a Claas C508 head. Yesterday, it suddenly wanted to steer right with AutoPilot engaged. Attempted to disengage by turning steering wheel (usually kicks it out) and had to really fight the wheel to do so. Disengaged it with button on handle, but still had to be turning the wheel slowly to the left to drive a straight line. Flipped rocker switch on dash to shut system off, and things return to normal.

This is a 500 series (pre-CAN?), and I 'think' that the 700's are steer by wire. I 'think' the 500's have the old hand pump in the column, and then run a 'bang-bang' valve for the AutoPilot (one that doesn't play well with others in the guidance world).

Our local support is a young Claas/Lexion franchise and the techs (who are great) are schooled primarily on the 700's. They have been helpful, but I brought this machine into the area on my own, so this is my problem...

With these symptoms, I'm leaning to the AutoPilot valve having a sticky plunger or something. When disengaged, it should be ignoring any signal from the row sensors, but it will still be trying to turn right. (Thank God, in Ontario, all politics seems to steer left...)

Anyone with similar experiences? Diagnose first, repair second preferred.

Thanks, Ken
 

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Discussion Starter · #3 ·
Do you have autosteer through gps that you can try it on an a-b line?

Don't forget your wheel angle sensor, if it has one.
Eddie,
I do have an EZ 250 that runs an EZ Steer when we're operating a platform head - It also feeds position data to the Insight.
The AutoPilot runs independently of either of these contraptions with the sensors on the head and a bang-bang valve on the machine. The bang-bang is Claas proprietary, doesn't play well with others, so that was why we use an EZ Steer for soys and wheat.

Will look into wheel angle sensor, but am dubious...

Thanks for the reply!

Ken
 

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Don't forget your wheel angle sensor, if it has one.
+1. If there steering sensor is reading low voltage (but not necessarily 0.00V), it will think that the wheels are turned all the way to one side, and will start driving the valve to correct this. Normally the sensors will have a calibrated range of around 0.5V to 4.5V, with 2.5V being roughly in the middle.

On a Trimble AutoPilot, there will be a message along the lines of "Steering opposite to command" or "FET Coil short to ground/open" etc to say that the valve doesn't appear to be reacting to the commands sent by the controller.
 

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If it has a steering angle sensor like my 2011 740, it is built into the left steering cylinder, internally. I was getting an error message in the mornings with the "touch arms" activated in CEBIS. "steering angle sensor defective" or something like that. If you have one, take a sharp voltage meter and check the ground, that it is good, the power wire (probably has about 4.5 volts) and the signal wire. Signal wire is usually the middle wire and should be a smooth reading from about .5 -4.5 volts within the steering angle range.

I don't know your dealer but Ziegler has a 1-800 number for tech support. They are very knowledgeable and helpful when it comes to troubleshooting things like this.
 

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Discussion Starter · #6 ·
Update !!!


I recalled I'd posted this question a couple of years ago....


After locating the harness for the wheel angle position sensor, checking voltages, fiddling around...


Swapped out the AutoPilot module for a 'known' good one.... It works.


Module Failure.
Not what we wanted to find out $$$, but an easy fix.... Better than tracing a wiring harness for 3 days looking for the pinched spot.


Just wanted to update.
Ken
 

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Is the autopilot module a common module on the machine that can be swapped with others, such as the sieve module?

I recently got tired of random "steering angle signal defective" or whatever it was. I bought a potentiometer just like the lateral tilt and feederhouse height uses and mounted it on the rear axle. With some linkage attached to the front tie-rod, and a new connector for the original wheel angle sensor wiring, I now have good WAS. This was a much cheaper alternative than rebuilding the sensor within the steering cylinder, or buying new cylinder like they claim you're money ahead to do.
 

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Discussion Starter · #8 ·
Is the autopilot module a common module on the machine that can be swapped with others, such as the sieve module?

I recently got tired of random "steering angle signal defective" or whatever it was. I bought a potentiometer just like the lateral tilt and feederhouse height uses and mounted it on the rear axle. With some linkage attached to the front tie-rod, and a new connector for the original wheel angle sensor wiring, I now have good WAS. This was a much cheaper alternative than rebuilding the sensor within the steering cylinder, or buying new cylinder like they claim you're money ahead to do.
Eddie. The module is common to machines of a similar series. I think there were some significant changes in the autosteer / AutoPilot systems between the 500 and 700 series. We found a module for a 500 series with factory AutoPilot, and swapped it out with ours. AutoPilot works perfect now.
This was actually suggested by a Ziegler tech when I described the symptoms. He asked about the wheel position sensor in the cylinder, we had checked it out, found it returning voltage in the correct range, and the ground was good. He suggests then its either module failure or a pinched wire. Easiest way to rule the module out is to replace it with one from another machine. If that fixes it, its the module. If it doesn't, start looking for a wiring issue.
I'm glad the module fixed it.... Finding a wiring issue: Needle, meet haystack!


They are $ proud $ of both the cylinders and the modules...


Ken
 

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Ken is correct. The 400/500 series AP uses different sensors and modules than the 6/700 series. I also believe the valves are different, although they continued to use a bang-bang valve up until 2016.
 
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