Case IH AFX8010 Repair Manual page 1396

Control valve - Open circuit (C.20.F.13 - G.30.B.50)
AFX8010
E0179-05 - Ground Drive Hydro Current Sense
Cause:
The ground speed hydrostat solenoid L-23 circuit is open.
Possible failure modes:
1. Failed solenoid.
2. Circuit return side wiring is open.
3. Controller internal failure (internal regulator failure).
Solution:
1. The ground drive hydro current sense circuit is the ground path for the ground speed hydrostat solenoid circuit.
By monitoring current flow on the return path of the ground speed hydrostat solenoid, the CCM-2 module can
provide precise control of the solenoid engagement. When this error message is reported, this is an indication
of very low current draw on the circuit, or an open circuit on the return line.
Enter the Universal Display Plus "DIAG" screen. Select the "GROUND DRIVE" sort menu, and select "HYDRO
ISENSE" to check the voltage range. Move the propulsion handle to the full forward position, the full rearward
position, and back to the neutral position while monitoring the voltage.
With the propulsion handle in neutral, the voltage indicated should be 0 volts.
With the propulsion handle in the full forward position, the voltage indicates should be approximately 4.4 volts.
With the propulsion handle in the full rearward position, the voltage indicated should be approximately
2.5 volts.
The fault code is generated if the current flow is less than 5 mA (0.2 volts indicated on bar graph) at any
time when the propulsion handle is out of neutral.
A. If one or both of the readings are less than 0.2 volts, continue with step 2.
B. If the readings are normal, continue the troubleshooting at step 7.
2. Turn the key switch to the OFF position, and disconnect the ground speed hydrostat solenoid connector
X100. Use a multimeter to check the resistance of the ground speed solenoid L-23 between connector X100
pins A & B (rev) and connector X100 pins C & D (fwd). The proper resistance range for the ground speed
solenoid is 16k - 20k ohms.
A. If out of specification, replace the solenoid.
B. If the solenoid is within specification, continue with step 3.
3. Use a multimeter to check for continuity between the harness end of connector X100 pins B & C and chassis
ground. There should be approximately 50 ohms resistance measured between each pin and chassis ground.
A. If there is continuity to ground on connector X100 pin B, but not pin C, there is an open circuit in the
gearbox (GB) harness between connector X100 pin C and the harness splice wire 887 blue. Locate
the open and repair.
B. If there is continuity to ground on connector X100 pin C, but not pin B, there is an open circuit in the
gearbox (GB) harness between connector X100 pin B and the harness splice wire 886 blue. Locate
the open and repair.
C. If there is no continuity on either pin, continue with step 4.
4. Disconnect connector X011. Use a multimeter to check for continuity between the main frame (MF) harness
end of connector X011 pin 7 and chassis ground. There should be approximately 50 ohms resistance to
chassis ground.
POWER TRAIN - TRANSMISSION Hydrostatic
9681 1 27/05/2004
C.20.F / 24