E0040-03-Ccm1 Key Switch Voltage Shorted To High Source (A.50.A.91.81 - G.30.B.54) - New Holland CX720 Repair Manual

E0040-03-CCM1 Key Switch Voltage Shorted To High Source
(A.50.A.91.81 - G.30.B.54)
E0040-03 - CCM1 Key Switch Voltage Shorted To High Source
Cause:
The circuit is shorted to a higher than normal source.
Possible failure modes:
1. Circuit wiring shorted to high voltage source.
2. Faulty alternator/regulator.
3. Controller internal failure (internal regulator failure).
Solution:
1. Key switch voltage is used to initialize (wake-up) the module, and also supplies power to the 5 - 8 V regulators
for the regulated voltage circuits. The module will shutdown if the voltage is less than 9 volts, but there is no
shutdown for excessive voltage.
Start the combine engine. Enter the InfoView Monitor - "Diagnose info" screen.
Select "Supply" sub menu.
Select "CCM1 Key switch Voltage". Increase the engine RPM to high idle (maximum) and check voltage range.
The acceptable voltage range for the module is 10 - 18 volts.
A. If the voltage reading is greater than 18 volts, continue with Step 2.
B. If the voltage reading is between 10 - 18 volts, go to Step 5.
2. Shut off the combine engine, and then turn the key switch on again. Enter the InfoView Monitor - "Diagnose
info" screen.
Select "Supply" sub menu.
Select "CCM1 Key switch Voltage" and check voltage range.
The acceptable voltage range for the module is 10 - 18 volts.
A. If the voltage reading is between 10 - 18 volts, the alternator and/or regulator has failed, and is producing
excessive voltage. Refer to Alternator - Testing (A.30.A.82 - G.40.A.20) for additional alternator testing
information.
B. If the voltage reading is greater than 18 volts, continue with Step 3.
3. Turn the key switch off to power down the system. Check the voltage at fuse F38 using a multi-meter.
A. If the voltage reading is greater than 18 volts,then the batteries have been mistakenly connected in series
(7.5L units), or there is a fault in the wiring of the 24 V starting system (Iveco units). Refer to Start control
- Troubleshooting (B.80.A.90 - G.40.A.10) for additional information.
B. If the voltage reading is between 10 - 18 volts, continue with Step 4.
4. Remove the buddy seat and storage bin to gain access to connector X018 on CCM1. Turn the key on. Check
the voltage at connector X018 pin J1-4.
A. If the voltage reading is greater than 18 volts, then a high voltage source has been connected to one of
the following wires in the cab main harness.
Wire 053 red, fuse F38 to key switch S02 pin 1
Wire 125 red, fuse F38 to ECU Power relay K14 pin 1
Wire 859 orange, key switch S02 pin 5 to ECU connector X193 pin 15 (Series 1238 and above)
Wire 096 orange, key switch S02 pin 6 to CM harness splice
Wire 055 orange, CM harness splice to Road Light switch S26 pin 6
Wire 095 orange, CM harness splice to CCM1 Power relay K24 pin 1
Wire 103 orange, CCM1 power relay K24 pin 1 to CCM2 Power relay K25 pin 1
DISTRIBUTION SYSTEMS - ELECTRONIC SYSTEM
A.50.A / 88
2 4/7/2006