New Holland CX720 Repair Manual page 2444

E0142-05-Groundspeed RPM sensor Line Disconnected
(C.20.B.95.80 - G.30.B.50)
E0142-05 - Groundspeed RPM sensor Line Disconnected
Cause:
The ground speed RPM sensor (B-17) circuit is open.
Possible failure modes:
1. Sensor supply or ground wiring is open.
2. Controller internal failure (internal regulator failure).
Solution:
1. Enter the InfoView monitor - "Diagnose info" screen.
Select "Driveline" sub menu.
Select "Groundspeed RPM sensor" and check voltage range.
The proper voltage sensor blocked by ferrous metal - 5.6 - 7.3 volts
The proper voltage sensor unblocked by ferrous metal - 0.5 - 5.6 volts
The proper voltage sensor disconnected 7.3 - 9.0 volts.
A. If the voltage reading is high 7.3 - 9.0 volts continue with Step 2.
B. If the voltage reading is within the proper limits. Continue the troubleshooting at step 6.
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.
2. The voltage reading on the Infoview monitor is 7.3 - 9.0 volts. Disconnect the ground speed RPM sensor con-
nector X087. Use a jumper wire to short pin B on the harness end of connector X087 to 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 7.3 - 9.0 volts continue with Step 3.
3. The voltage reading on the InfoView monitor is 7.3 - 9.0 volts. Disconnect the lower frame harness from the
front frame harness at connector X023. Use a jumper wire to short pin 6 on connector X023 to ground.
A. If the InfoView monitor drops to 0 - 0.5 volts indicating a ground, the open circuit is in the lower frame (LF)
harness between connector X023 pin 6 and connector X087 pin B wire 403 yellow. Locate the open and
repair.
B. If the InfoView monitor still displays 7.3 - 9.0 volts, the open circuit is in the front frame (FF) harness
between connector X023 pin 6 and connector X017 pin J3-14 wire 403 yellow. Locate the open and
repair.
4. Disconnect the ground speed RPM sensor connector X087. Use a multimeter to check for continuity between
the harness end of connector X087 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 lower frame harness from the front frame harness at connector X023. Use a multimeter to check
for continuity between the harness end of connector X023 pin 5 and chassis ground.
A. If there is continuity, the open circuit is in the lower frame (LF) harness between connector X023 pin 5 and
connector X087 pin A wire 717 blue or 042 blue. Locate the open and repair.
POWER TRAIN - TRANSMISSION Mechanical
2 4/7/2006
C.20.B / 106