New Holland CX720 Repair Manual page 2412

E0645-05-Gear Select Input Line Disconnected (C.20.B.05.80 -
G.30.B.50)
E0645-05 - Gear Select Input Line Disconnected
Cause:
The Right Hand Module (RHM) has detected that the Gear Select Input circuit voltage is <0.2 volts .
Possible failure modes:
1. The Gear Select Input circuit is open or reduced to <0.2 volts .
2. Gear Select Switch S-24 failure.
3. RHM internal failure.
Solution:
1. Verify the fault is present. Enter the Infoview monitor - "Diagnose info" screen, "Console" sub menu. Select
"Gear Select Input" and observe the voltage.
The normal operating range for the Gear Select Input circuit is 0.2 - 4.75 volts .
A. If the voltage reading is <0.2 volts , continue with Step 2.
B. If the voltage reading is within the proper limits, the fault may be intermittent. Continue troubleshooting at
Step 6.
2. Verify the power supply and ground are good. Using a voltmeter, measure the voltage between the connector
X048 pin B(-) and pin A(+) at Gear Select Switch S-24.
A. If the voltage reads between 4.500 - 5.500 volts the RHM 5V Reference and circuit ground are both good.
Continue troubleshooting at Step 3.
B. If the voltage is below 4.500 volts, then the RHM 5V Reference is missing. Check for a E0641-04 -
RHM 5V Reference fault. If present, correct that fault and resume operation. Otherwise, repair the open
between the Right Console harness X026 pin 17 and Gear Select Switch connector X048 pin A, or between
Right Console harness connector X026 pin 7 and Gear Select Switch connector X048 pin B. Continue
troubleshooting at Step 6.
3. Verify Gear Select Switch S-24 is good. Disconnect Gear Select Switch S-24. Using an ohmmeter, measure
the resistance between the pins of the Gear Select Switch S-24 connector X048 according to the table below.
Switch PIN
Position
1 A
2 A
N A
3 A
4 A
A. If the switch tests good, continue troubleshooting at Step 4.
B. If any resistor circuit is found to be open or out of range, replace Gear Select Switch S-24. Continue
troubleshooting at Step 6.
4. Verify circuit 391 yellow is good. Measure the continuity between RHM X027 pin 11 and Gear Select Switch
S-24 connector X048 (harness side) pin C.
A. If the circuit tests good, continue troubleshooting at Step 5.
B. If the circuit is open, locate and repair the open. Continue troubleshooting at Step 6.
5. Verify the RHM is good. Observe the "Gear Select Input" voltage on the Infoview monitor.
POWER TRAIN - TRANSMISSION Mechanical
OHMS PIN
1121-1239 C
1121-1239 C
1121-1239 C
1121-1239 C
1121-1239 C
2 4/7/2006
C.20.B / 74
OHMS PIN
192-212 B
242-268 B
342-378 B
542-599 B
1596-1764 B
OHMS PIN
971-1073 A
1021-1129 A
1121-1239 A
1321-1460 A
2375-2625 A