New Holland CX720 Repair Manual page 2649

E0025-05-Gearbox Temp Sensor Line Disconnected (C.50.B.95.90 -
G.30.B.50)
CX720 Series 1238 and above, CX740 Series 1238 and above, CX760 Series 1238 and above, CX780 Series 1238 and above, CX820 Series 1238 and
above, CX840 Series 1238 and above, CX860 Series 1238 and above, CX880 Series 1238 and above
E0025-05 - Gearbox Temp Sensor Line Disconnected
NOTE: This troubleshooting chart is for CX combines Series 1238 and above.
Cause:
The gearbox temperature sensor (B-32) circuit is open.
Possible failure modes:
1. Sensor supply wiring is open.
2. Controller internal failure (internal regulator failure).
Solution:
1. Enter the InfoView monitor - "Diagnose info" screen.
Select "Hydraulics" sub menu.
Select "Gearbox Temp sensor" and check voltage range.
The normal operating range for the sensor is 0.5 - 4.9 volts.
If there is an open in the supply or ground wiring, the voltage will be 4.9 - 5.2 volts.
A. If the voltage reading is high 4.9 - 5.2 volts continue with Step 2.
B. If the voltage reading is within the proper limits, the open is not present at this time. Continue the trou-
bleshooting at step 7.
NOTE: Visually inspect the wiring harness and connectors. Verify that the connector was fully installed. Inspect
the terminals and wires at the connector for pushed back or corroded terminals or damaged wires. Flex the
harnesses involved to reveal intermittent breaks or shorts in the wiring concerned.
2. The voltage reading on the InfoView monitor is 4.9 - 5.2 volts. Disconnect the gearbox temperature sensor
connector X097. Use a jumper wire to short the harness end of connector X097 pin B to chassis ground.
A. If the InfoView monitor drops to 0 - 0.5 volts indicating a ground, the open circuit is not in the supply side
of the circuit. Continue with step 4.
B. If the InfoView monitor still displays 4.9 - 5.2 volts, continue with Step 3.
3. The voltage reading on the InfoView monitor is 4.9 - 5.2 volts. Disconnect the gearbox harness from the main
frame harness at connector X011. Use a jumper wire to short connector X011 pin A to chassis ground.
A. If the InfoView monitor drops to 0 - 0.5 volts indicating a ground, the open circuit is in the gearbox (GB)
harness between connector X011 pin A and connector X097 pin B wire 422 yellow. Locate the open and
repair.
B. If the InfoView monitor still displays 4.9 - 5.2 volts, the open circuit is in the main frame (MF) harness
between connector X011 pin A and connector X019 pin J2-27 wire 422 yellow. Locate the open and
repair.
4. Disconnect the gearbox temperature sensor connector X097. Use a multimeter to check for continuity between
the harness end of connector X097 pin A and chassis ground.
A. If there is continuity, the ground path for the sensor is complete, and the fault is in the sensor itself. Replace
the sensor.
B. If there is no continuity to ground, the ground path for the sensor is open. Continue with step 5.
5. Disconnect the gearbox harness from the main frame harness at connector X011. Use a multimeter to check
for continuity between the harness end of connector X011 pin H and chassis ground.
POWER TRAIN - PROCESS DRIVE Primary process drive
2 4/7/2006
C.50.B / 85