Any idea? 3520 : Err 06

[manias]

Hi,

I was plowing snow when out of nowhere I got a Err 06 : No signal at MFWD speed input.

The traveling speed display now read 0 mph. I no longer see the error tough and error light is off.

Does any one know where is the MFWD speed sensor so I can check if it's disconnected? I'm on ice chain so maybe vibration got thing loose.

 

[Cocre]

I can't tell the exact location by looking at the manual.

The technical manual says; "Test MFWD sensor. Check that MFWD is fully engaged. Check 502 Red wire and connections for short or open circuit."

It gives several pages of instructions on how to test the sensor using different methods. Plus electrical schematics. Following is the preferred method.

eHydro - MFWD Speed Sensor Test
Purpose:
The MFWD speed sensor is tested based upon the proper
voltage input and frequency output during a drive function.
The display panel (Diagnostic mode 2, preferred method)
or the test kit (JDG1575, optional method) or SERVICE
ADVISOR (optional method) can be used to test the
MFWD speed sensor.
Procedure - Diagnostic Mode 2:
Test Conditions:
Machine on jack stands.
Operator on seat.
Engine running with throttle at low idle.
Transmission in gear position A.
Park brake unlocked.
1. Verify engine speed is set within specification. See
Slow Idle Adjustment on page 54 in the Engine section.
2. Park machine safely and set to test conditions.
3. Enter the diagnostic mode 2. See Diagnostic Mode 2
(eHydro/Auto HST): on page 346.
4. Toggle the right turn signal switch to display position 11
(gSXXXX) for ground speed.
5. With the engine running at low idle and the range
transmission in gear position A, fully depress the forward
drive pedal and note the frequency reading on the display
panel. Move the throttle lever to the fast idle position and
note display reading.
6. Release the forward pedal, move the throttle lever to the
low idle position and shift the range transmission to gear
position B. Go to Step 5.
7. Release the forward pedal, move the throttle lever to the
low idle position and shift the range transmission to gear
position C. Go to Step 5.
8. If the frequency readings are not within specification,
MFWD Specification: on page 361), replace the
MFWD speed sensor..


Diagnostic Mode 2 (eHydro/Auto HST):
Note: The password is different for each access mode.
R = Right and L = Left on the turn signal switch.
1. Enter password, LRRRLR. Use this password to get the
information that is within the eHydro/Auto HST controller.
2. In this mode, Display controller communicates with the
eHydro controller to get the parameters as listed in the
following table.
Note: The diagnostic values are displayed live. The
values displayed will change (after refreshing the
display by cycling the display to the next higher or
lower address and then returning to the original
address) if the components for the item selected are
changed. Example, when the forward pedal voltage
(No. 17) is displayed, if the forward pedal is pressed,
the voltage reading on the display will also change
(after cycling).
3. Use left (B) or right (C) turn signal switch to navigate
through the parameters.

MFWD Specification:
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . 5.0 ｱ 0.2 volts
Gear A - Frequency at Low Idle. . . . . . . . . 233 ｱ 0.1 kHz
Gear A - Frequency at High Idle . . . . . . . . 650 ｱ 2.0 kHz
Gear B - Frequency at Low Idle. . . . . . . . . 414 ｱ 0.1 kHz
Gear B - Frequency at High Idle . . . . . . . . 710 ｱ 2.0 kHz
Gear C - Frequency at Low Idle. . . . . . . . . 970 ｱ 0.1 kHz
Gear C - Frequency at High Idle . . . . . . . 2923 ｱ 2.0 kHz

 

[manias]

Thanks you very much! I'll update when I found out what's wrong!

 

[zr2blz]

My 3320 was only a month old when it started getting 06 codes in Jan 08. I was at son's place and it was cold (-10 to 32) for whole month. It would start fine and I could see mph for a little while (forward or backward) and then 06 would pop up.

I was pushing and rear plowing a lot of snow around and had chains on all 4 (v-link car chains on front) with R4s. Was at 8500' and it snowed almost every day. I was keeping main road and his driveway open as he was moving into a new house (on 2/22/08).

So, on 2/17/08 I started 3320 in garage (was plug'd in) and got error 12. It wouldn't move. Stop / start again, nope. After 5th try it moved with no error 12. I put 3320 on my 16' trailer and took to nearest JD dealer (50 miles away) after talking to my dealer (160 miles away) to see what I should do/try next.

They swapped out the MFWD Speed Sensor with a new 3x20. That was the problem, so they ordered me a new sensor. Took 5 days for me to get tractor back (left trailer with them as they couldn't unload it until it was fixed). When I got it back and until now, the error 06 has NOT come back. So, replacing the sensor fixed the error 12 and error 06.

Good luck (I now have 420 hr on mine).

 

[RogerH]

The MFWD speed sensor is located on the side of the transmission on the right side. Look under the foot platform, I think toward the rear of the platform. There should be a 6"-8" wire coming out with a 3 pin connector.

 

[Spudland_Dave]

Yep..had it happen to mine too with only 2-3 hours on the clock. Speed sensor....someone on here posted the attached pic. Real easy to change, my dealer knew what it was right away and gave me a sensor (In stock) to take home and replace it.
The sensor is at the bottom of the pic...little white dot on the head of the bolt...
Took 5 mins to replace, only tip I was given was to rub some Vaseline on the O-Ring on the sensor...remove the old one and have the new one ready as hydraulic oil will pour out of the hole...remove & replace.

 

[manias]

Thanks all, you were all right, it was the sensor!
Took me about 4-5 min to change. I'm glad you did post this pic so I could locate it!

 

[aigeezer]

My JD3520 with 42 hours just started showing error code 6 today as I was plowing snow. Thanks to this thread I'll know what to look for. The Internet never forgets! Thanks, all.

 

[aigeezer]

Today I followed the advice here and found the 3-pin connector to the sensor had separated, probably from the pressure of deep snow pushing against it. It clicked together easily and I routed it a bit higher for "next time". Easy stuff. Oh, I used an old flat carton from a storm door to put under the tractor so I didn't have to lie in the mud. That's a keeper! Thanks again for the good information.