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tm1606 - 670C, 670CH, 672CH 770C, 770CH, 772CH Motor Graders

Operationand Test
Transmission Diagnostic Trouble Codes F323-F329

Transmission Diagnostic Trouble Codes F323-F329

Troubleshooting Tips F323-F329 Start-Up Diagnostic Trouble Codes

Incorrect interaction of forward/reverse switch module, park brake/gear position module and park brake off psi switch. These
codes occur when shifting from park or neutral into gear.

-: START-UP SERVICE CODES F323-F329

SERVICE TECH MANUAL MACHINE

CODE DESCRIPTION POSSIBLE CAUSE OPERATION SOLUTION
F323 Neutral and Gear at Top shifter plate Neutral Only Check top plate for damage, excessive wear
On same time. loose or missing. Reset in park or loose screws.
Occurrence S7 Forward/reverse
switch module, S6
Park/Not Neutral Gear
Position Switch Module.
Forward/reverse switch
indicates in forward or
reverse, when shift
handle switches indicate
not in gear and not park
switch is in park.
Transmission Ensure that the run plug is properly seated.
calibration Check for continuity in the run jumper plug.
connector has a bad Check continuity from transmission calibration
connection. connector to park start reset relay.
Forward-T14 BLU
Wire
Reverse-T01 BLU
Wire
S7 Start machine, depress inching pedal, and
Forward/Reverse move shift handle through all gears; forward,
Switch Module reverse, and neutral. Observe monitor display
window to see if display matches transmission
control lever position. If display window does
not match lever position, see switch check in
9015-15 Transmission Controller Circuit.
Mechanical linkage Replace shift handle.
problem.
Shorted to battery Disconnect S7 Forward/Reverse Switch
voltage. Module connector from S7 Forward/Reverse
Forward T14 BLU Switch Module switch. Measure the voltage on
Wire or Reverse the S7 Forward/Reverse Switch Module wires.
T01 BLU Wire Voltage should be GND. If not disconnect the
Transmission Controller Unit (TCU) and
measure again. If the wires are still high, check
the harness for a short to battery voltage. Else
replace the TCU

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F324 Not in Forward or Some shifters may intermittently Neutral Tolerance condition in the assembly
On Reverse while in gear. malfunction in this way. It can be Only: and wear of the shifter. Repair or
Occurrence Forward/Reverse switch tested for by pulling hard and fast on Reset in replace.
indicates shift handle is the shifter handle toward higher gear Park
in neutral while the shift as you slide around the edge from
handle is in a gear. neutral into gear. Test by shifting from
1 forward to 1 reverse and back and
forth with the shift handle in contact at
all times with the piece of metal
between forward and reverse.
Mechanical linkage problem. Replace shift handle.
Forward/Reverse Switch Assembly Start machine, depress inching
pedal, and move shift handle
through all gears; forward, reverse,
and neutral. Observe monitor
display window to see if display
matches transmission control lever
position. If display window does not
match lever position, see switch
check in 9015-15 Transmission
Controller Circuit.
Forward or reverse wire open; Disconnect Forward/Reverse
T14 BLU Wire to TCU J1-J1 connector from Forward/Reverse
switch and disconnect the TCU.
T01 BLU Wire to TCU J1-J2 Check the wires from the TCU to
the Forward/Reverse connector for
continuity. If no continuity then
check connector crimps and
harness.
Power connection to the Remove the connector from the
Forward/Reverse switch is bad. Forward/Reverse switch. Measure
P02 Red Wire the voltage on pin H of the
connector. It should be battery
voltage. See Forward/Reverse
switch check in 9015-15
Transmission Controller Circuit.

F325 Forward Top plate loose or Neutral Check top plate for damage, excessive wear, or loose screws.
On and missing. Only
Occurrence Reverse on Reset
at same in Park
time
S7 Forward/Reverse Start machine, depress inching pedal, and move shift handle
Switch Module through all gears; forward, reverse, and neutral. Observe
monitor display window to see if display matches transmission
control lever position. If display window does not match lever
position, see switch check in 9015-15 Transmission Controller
Circuit.
Forward or Reverse Disconnect S7 Forward/Reverse Switch Module connector from
wire shorted to S7 Forward/Reverse Switch Module switch. Measure the voltage
battery voltage. on the S7 Forward/Reverse Switch Module wires. Voltage
T14 BLU Wire for should be GND. If not disconnect the Transmission Controller
Forward Unit (TCU) and measure again. If the wires are still high, check
the harness for a short to battery voltage. Else replace the TCU.
T01 BLU Wire for
Reverse

F326 Shifter Handle in Neutral or Park brake Neutral Cold weather and Oil is very heavy, let
On gear and park brake stays on. releasing slowly. Only machine idle and warm up longer. Slow
Occurrence 2 seconds is allowed for the park Reset in reacting Pressure switch.
brake to come off after shifting Neutral
from Park to neutral or gear.

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Machine shifted Allow transmission pressure to reach

from Park too fast. operating pressure after startup before
shifting from park. Allow machine to idle for a
short period of time before shifting from park.
Blown Park Brake Replace F2 Park Brake Fuse.
Fuse.
Y2 Park Brake Check connector on the park brake release
Release Solenoid solenoid. Make sure it is seated properly and
is disconnected or that the contacts are not corroded.
bad.
B7 Park Brake On Start machine and shift to neutral, use the
Pressure Switch. blade of the machine to move the vehicle. If
machine rolls, it indicated that the park brake
released. Replace sensor. See B7 Park
Brake On Pressure Switch in 9015-15
Start/Park Brake Circuit.
X27 Transmission Calibrate H04 GRN and H07 Check wiring harness. See Transmission
Connector GRN Wires are Controller Circuit Schematic in 9015-15.
open.
S6 Park/Not Neutral Gear Brake will Not Do Park Brake Pressure Test. See 9020-25,
Position Switch Module indicates pressurize to Park Brake Pressure Test.
handle is in Neutral or gear. B7 release park brake
park brake on pressure switch
indicates that the park brake is
on.
Park = Battery Voltage
Park Brake on Pressure Switch =
Battery Voltage
S6 Park/Not Disconnect the park switch. Measure for
Neutral Gear continuity from Pin F-E in neutral, and open
Position Switch when in Park. See S6 Park/Not Neutral Gear
Module Position Switch in 9015-15 Transmission
Controller Circuit.

F327 Shifter handle is in Transmission Neutral Ensure that the run plug is properly seated. Check for
On Forward or calibration connector Only continuity in the transmission calibration connector.
Occurrence Reverse and Park has a bad connection. Reset Check continuity from transmission calibration
Brake comes on. Wire P61 RED from in Park connector harness to K2 Park Start Reset Relay.
2 seconds is K2 Park Start Reset
allowed for the park Relay
brake to come off
after shifting from
park to neutral or
gear.
Forward/Reverse Start machine, depress inching pedal, and move shift
Switch Assembly. handle through all gears; forward, reverse, and neutral.
Observe monitor display window to see if display
matches transmission control lever position. If display
window does not match lever position, see switch
check in 9015-15 Transmission Controller Circuit.
Bad connection at Disconnect TCU monitor voltage on TCU connector.
TCU. Pin J1-K1 at Shift from Park to Neutral. The voltage should be GND
TCU, wire H07 GRN. in Park and battery voltage in Neutral. If not, check
wire-pin crimp for good contact.
S6 Park/Not Neutral Disconnect the park switch. Measure for continuity from
Gear Position Switch Pin F-E in neutral, and open when in Park. See S6
Module. Park/Not Neutral Gear Position Switch in 9015-15
Transmission Controller Circuit.

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F328 Park Brake On with Forward/Reverse Neutral Only Start machine, depress inching pedal,
Store Shifter in Park Switch Assembly. Reset in Neutral and move shift handle through all gears;
Only Position, with at least forward, reverse, and neutral. Observe
one gear position monitor display window to see if display
switch on. matches transmission control lever
Shift handle is not in position. If display window does not
Park, but monitor says match lever position, see switch check
park "P". in 9015-15 Transmission Controller
Circuit.
Park switch indicates
handle is in Park.
Gear switch indicates
handle is in gear.
Forward/Reverse
switch indicates handle
is in Neutral or Park.
Park = GND
Gear = 3 at Battery
Voltage
Forward/Reverse =
GND
(A) W21 WHT-TCU J2-
B1
(B) W17 WHT-TCU J2-
A2
(C) W18 WHT-TCU J2-
A3
(D) W19 WHT-TCU J1-
H3
(E) W20 WHT-TCU J1-
H2
Transmission Ensure that the run plug is
calibration connector properly seated. Check for
has a bad continuity in the transmission
connection. calibration connector. Check
continuity from transmission
calibration connector
harness to K2 Park Start
Reset Relay.
Disconnect TCU and shift to
park. Measure the voltage
on the TCU connector.
Gear shifter wires Park ABCDE=GND
are shorted to Neutral ABCDE=GND
Voltage
1 st ABC=battery voltage DE=GND
2 nd BCD=battery voltage EA=GND
3 rd DE=battery voltage AB=GND
4 th DEA=battery voltage BC=GND
5 th EAB=battery voltage CD=GND
6 th ABD=battery voltage CE=GND
7 th BDE=battery voltage CA=GND
8 th BCE=battery voltage AD=GND
If ok see bench test of switch assembly
in 9015-25.

F329 S6 Park/Not Neutral Gear Position Switch B7 Park Brake On Neutral Replace B7 Park Brake
On Module or B7 Park Brake On Pressure Pressure Switch is too Only On Pressure Switch.

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Occurrence Switch problem. sensitive. Check all wiring

Wiring changed to associated with Park
override Park Brake Brake Circuit.
Circuit.

CED,TX17864,1052-19-20000114

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