New Holland CX720 Repair Manual page 2561

E0135-05-Charge Pressure Switch Line Disconnected (C.20.F.95.86
- G.30.B.50)
E0135-05 - Charge Pressure Switch Line Disconnected
Cause:
The charge pressure switch (S-37) circuit is open.
Possible failure modes:
1. Sensor supply or ground wiring is open.
2. Controller internal failure (internal regulator failure).
Solution:
1. The charge pressure switch is normally closed when there is no pressure (engine not running), and open when
there is pressure (engine running). The check for an open circuit only occurs when the electrical system is
initially powered up before the engine is started.
Enter the Info View Monitor - "Diagnose info" screen.
Select "Driveline" sub menu.
Select "Charge pressure switch" and check voltage range.
The proper voltage range for the charge pressure switch when the engine is not running is 1.8 volts or less.
A. If the voltage reading is high (1.8 - 10 volts), continue with Step 2.
B. If the voltage reading is within the proper limits, since the shorted wire may not be powered up at this time.
Continue the troubleshooting at step 4.
2. The voltage reading on the Infoview monitor is high. Disconnect the charge pressure switch connector X101
ring terminal and ground the terminal to the chassis.
A. If the voltage drops back into the proper range (0 - 1.8 volts), the switch has failed open. Replace the
switch.
B. If the voltage remains high on Infoview monitor, continue with Step 3.
3. The voltage reading on the Infoview monitor is high. Disconnect the gearbox harness from the main frame
harness at connector X011 and provide a ground to pin W.
A. If the voltage drops back into the proper range (0 - 1,8 volts), the open is in the gearbox (GB) harness
between the switch connector X101 and connector X011 pin W wire 684 yellow. Locate open and repair.
B. If the voltage remains high on Infoview monitor, the open circuit is in the main frame (MF) harness between
connector X011 pin W and connector X016 pin J2-35 wire 684 yellow. Locate open and repair.
4. Operate the machine while monitoring Infoview display.
A. If no high out of range readings are indicated, erase the fault code and continue operation.
POWER TRAIN - TRANSMISSION Hydrostatic
2 4/7/2006
C.20.F / 109