New Holland CX720 Repair Manual page 2443

E0142-04-Groundspeed RPM sensor Shorted To Low Source
(C.20.B.95.80 - G.30.B.53)
E0142-04 - Groundspeed RPM sensor Shorted To Low Source
Cause:
The ground speed RPM sensor (B-17) circuit is shorted to ground.
Possible failure modes:
1. Sensor supply wiring shorted to ground.
2. Controller internal failure (internal regulator failure).
Solution:
1. Enter the InfoView Monitor - "Diagnose info" screen.
Select "Drivemine" 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 low (0 - 0.5 volts), continue with Step 2.
B. If the voltage reading is within the proper limits, continue the troubleshooting at step 4.
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 low. Disconnect the ground speed RPM sensor connector X087.
A. If the voltage increases to 7.3 - 9.0 volts, the short is in the sensor or sensor wiring. Replace the sensor.
B. If the voltage remains low on InfoView display, continue with Step 3.
3. The voltage reading on the InfoView monitor is low. Disconnect the lower frame harness from the front frame
harness at connector X023.
A. If the voltage increases to 7.3 - 9.0 volts, the short is in the lower frame (LF) harness between connector
X023 pin 6 and connector X087 pin B wire 403 yellow.
B. If the voltage remains low, the short circuit is in the front frame harness between connector X023 pin 6
and connector X017 pin J3-14 wire 403 yellow.
4. Turn the key to ON position. Observing the LED on the harness end side of the sensor, place ferrous metal in
front of sensor then remove. The sensor is functioning If LED changes state.
A.
POWER TRAIN - TRANSMISSION Mechanical
2 4/7/2006
C.20.B / 105