777D Off-Highway Truck FKR00001-UP (MACHINE) POWERED BY 3508B Engine(S...
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Welcome: j040rhw
Product: TRUCK
Model: 777D TRUCK FKR
Configuration: 777D Off-Highway Truck FKR00001-UP (MACHINE) POWERED BY 3508B Engine
Troubleshooting
773D and 777D Off-Highway Truck/Tractors Caterpillar Monitoring System
Media Number -RENR8397-02 Publication Date -01/04/2009 Date Updated -05/10/2016
i02510465
Sensor Signal Voltage
SMCS - 7490-038-NS
System Operation Description:
Note: The main display module is connected.
Table 1
Sensor Voltage Specifications For The Sensor Voltage Test
100-3055 Temperature Sensor And 131-0427 Temperature Sensor
Temperature Signal Voltage(1) Duty Cycle
−20 to 0°C (−4 to 32°F) 1.1 to 1.4 DCV 11 to 15%
0 to 20°C (32 to 68°F) 1.4 to 2.0 DCV 15 to 23%
20 to 40°C (68 to 104°F) 2.0 to 3.1 DCV 23 to 37%
40 to 60°C (104 to 140°F) 3.1 to 4.5 DCV 37 to 55%
60 to 80°C (140 to 176°F) 4.5 to 5.7 DCV 55 to 71%
80 to 100°C (176 to 212°F) 5.7 to 6.6 DCV 71 to 82%
100 to 120°C (212 to 248°F) 6.6 to 7.2 DCV 82 to 89%
120 to 140°C (248 to 275°F) 7.2 to 7.4 DCV 89 to 93%
(1)
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These voltages are used as guidelines for troubleshooting and the voltages are not exact. The tolerance is ± 10%. The
tolerance is dependent on the condition of the harness. The output voltage should change smoothly as the temperature
changes.
Table 2
Sensor Voltage Specifications For The Sensor Voltage Test
3E-5370 Temperature Sensor And 131-0784 Temperature Sensor
Temperature Signal Voltage(1) Duty Cycle
−40 to 20°C (−40 to −4°F) 0.8 to 1.5 DCV 4 to 11%
−20 to 0°C (−4 to 32°F) 1.5 to 2.5 DCV 11 to 22%
0 to 20°C (32 to 68°F) 2.5 to 3.7 DCV 22 to 34%
20 to 40°C (68 to 104°F) 3.7 to 4.8 DCV 34 to 46%
40 to 60°C (104 to 140°F) 4.8 to 6.0 DCV 46 to 59%
60 to 80°C (140 to 176°F) 6.0 to 7.2 DCV 59 to 71%
80 to 100°C (176 to 212°F) 7.2 to 8.1 DCV 71 to 81%
100 to 120°C (212 to 248°F) 8.1 to 8.8 DCV 81 to 87%
120 to 140°C (248 to 275°F) 8.8 to 9.2 DCV 87 to 92%
(1)
These voltages are used as guidelines for troubleshooting and the voltages are not exact. The tolerance is ± 10%. The
tolerance is dependent on the condition of the harness. The output voltage should change smoothly as the temperature
changes.
Locate the suspect sensor. Identify the sensor wires and connector contacts. See Diagnostic Function,
"Pulse Width Modulated (PWM) Sensor - Test". DO NOT DISCONNECT ANY HARNESS
CONNECTORS AT THIS TIME. Turn the key start switch to the ON position. DO NOT START
THE ENGINE.
Test Step 1. CHECK THE SENSOR POWER.
A. At the sensor connector, identify the +V and ground circuits.
B. Push the 7X-1710 Cable Probes in the back of the sensor connector along side of the +V and
ground circuit wires.
C. Measure the system voltage.
Expected Result:
The voltage that is measured is between 7.5 and 8.5 DCV.
Results:
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• YES - The voltage is between 7.5 and 8.5 DCV. The system voltage is present. Proceed to test
step 2.
• NO - The voltage is not between 7.5 and 8.5 DCV. There is an open circuit. Trace the +V and
ground circuits in the machine harness.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 2. CHECK THE SIGNAL VOLTAGE.
A. At the sensor connector, identify the signal and ground circuits.
B. Push the 7X-1710 Cable Probes in the back of the sensor connector along side of the signal and
the ground circuit wires.
C. Measure the signal voltage and record the signal voltage.
Note: If a precise signal voltage is necessary, use the specifications that are listed in the
provided tables.
Expected Result:
The approximate signal voltage that is measured is between 1.0 and 7.0 DCV. When using the 3E-
5370 Temperature Sensor, the approximate signal voltage that is measured is between 1.0 and 9.0
DCV.
Results:
• FROM 1.0 TO 7.0 (9.0) DCV - The approximate signal voltage that is measured is between
1.0 and 7.0 DCV. When using the 3E-5370 Temperature Sensor, the approximate signal voltage
that is measured is between 1.0 and 9.0 DCV. The signal voltage at the sensor is correct.
Repair: The harness and the main display module are working properly. The voltage that is
measured is correct. The sensor has failed. Replace the sensor.
Proceed to test step 3.
• GREATER THAN 7.0 (9.0) - The approximate signal voltage that is measured is NOT
between 1.0 and 7.0 DCV. When using the 3E-5370 Temperature Sensor, the approximate
signal voltage that is measured is NOT between 1.0 and 9.0 DCV. The signal voltage is not
correct. The signal circuit of the machine harness is shorted to the +battery.
Repair: Repair the machine harness or replace the machine harness. Repeat this test step in
order to verify that the problem has been corrected. If the problem has not been corrected
replace the main display module. See Testing and Adjusting, "Module - Replace".
STOP
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• LESS THAN 1.0 DCV - The voltage is less than 1.0 DCV. The signal voltage is not correct.
The signal circuit of the machine harness is shorted to ground.
Repair: Repair the machine harness or replace the machine harness. Repeat this test step in
order to verify that the problem has been corrected. If the problem has not been corrected
replace the main display module. See Testing and Adjusting, "Module - Replace".
STOP
Test Step 3. CHECK THE SIGNAL CIRCUIT FOR THE MACHINE HARNESS .
A. At the machine harness connector for the main display module, identify the signal and ground
circuits.
Note: DO NOT DISCONNECT THE HARNESS CONNECTOR.
B. Push the 7X-1710 Cable Probes in the back of the machine harness connector along side of the
signal and ground circuit wires.
C. Measure the signal voltage.
D. Compare this measurement with the voltage that was measured in the previous test “Check the
signal voltage”.
Expected Result:
The main display module is receiving a valid signal voltage of 1.0 to 7.0 DCV.
Results:
• OK - The main display module is receiving a valid signal voltage. If the problem has been
corrected exit this procedure. No further testing is required. If the problem still persists, further
testing is required. Proceed to test step 4.
• NOT OK - The voltage is not the same as in the previous test "Check the signal voltage". The
machine harness has an open in the signal or ground circuits.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 4. Perform the following diagnostic procedure: "Sensor Dynamic Operation"
Results:
• OK - STOP
• REPAIRED, OK - STOP
Copyright 1993 - 2017 Caterpillar Inc. Tue Aug 22 21:50:25 UTC+0700 2017
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