PLATE 8D7833 - Caterpillar

Illustration 8 g01636200
Terminal locations at the left rail connector for the water level sensor
(Terminal 28) Digital supply
(Terminal 31) Digital return
(Terminal 50) Water level
Illustration 9 g01443926
Terminal locations at the machine interface connector for the water level sensor
(Terminal 15) Digital supply
(Terminal 17) Water level
(Terminal 33) Digital return
Illustration 10 g01635197
Terminal locations at the 4-pin connector for the water level sensor
(Terminal 1) Digital supply
(Terminal 2) Digital return
(Terminal 3) Water Level
(Terminal 4) Unused
Illustration 11 g01155187
Terminal locations at the integral connector for the water level sensor
(Terminal 1) Sensor reference
(Terminal 2) Sensor reference
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Remove electrical power from the ECM.
B. Thoroughly inspect the sensor connectors (3) and (4), ECM connectors (5) and (7), rail connector (6), and machine connector (8). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the fuel/water separator system.
D. Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Inspect Connectors and Wiring
Results: The harnesses and the wiring appear to be OK.
Proceed to Test Step 2.
Results: There is a problem with the connectors and/or the wiring.
Repair: Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.
2. Check the Supply Voltage at the Harness Connector for the Sensor
A. Disconnect the connector for the sensor module at the harness connector.
B. Restore electrical power to the ECM.
C. Measure the voltage between terminals 1 (digital supply) and 2 (digital return) on the harness side of the connector for the sensor module.
D. Remove electrical power from the ECM.
8.0 0.4 VDC
Results: The voltage measurement is 8.0 0.4 VDC. The supply voltage is reaching the sensor. Leave the harness connector disconnected at the sensor module.
Proceed to Test Step 3.
Results: The voltage measurement is not 8.0 0.4 VDC.
Repair: The digital sensor supply voltage is not reaching the sensor. There is a problem in the circuit for the digital sensor supply. Restore the wiring to the original configuration. Refer to Troubleshooting, "Sensor Supply - Test".
3. Use the "Fuel/Water Seperator Level Status" Parameter to Check for Proper Operation of the Sensor Module
A. Use a wire removal tool to remove the wire from terminal location 3 at the harness connector for the sensor module. Ensure that the loose end of the wire does not come into contact with any ground source or power supply.
B. Connect the harness connectors for the sensor module.
C. Restore electrical power to the ECM.
D. While an open circuit condition exists on the signal wire, monitor the status of "Fuel/Water Seperator