C7.1 Engines and Generator Sets Caterpillar

Water in Fuel - Test

Usage:

C7.1 770

For a 97-15 or 97-16 code, refer to Troubleshooting, "Fuel Contains Water" before returning to this procedure.

Use this procedure when the water-in-fuel sensor is suspect. This procedure also covers the following diagnostic code:

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Table 1
Diagnostic Trouble Code for the Water-in-Fuel Sensor
J1939 Code	CDL code	Code Description (code descriptions may vary	Comments
97-3	3547-3	Water In Fuel Indicator : Voltage Above Normal	The ECM detects the following conditions: An open circuit in the Water-In-Fuel (WIF) sensor circuit. The ECM has been powered for less than 5 seconds. The warning lamp will stay on when the "indicator lamp self check" has been completed. The ECM will disable the function to detect water in fuel while the code is active.

Water-in-Fuel Sensor Operation

The WIF sensor is a normally open sensor. During normal operation, there will be no signal sent from the WIF sensor to the ECM. If water is detected in the fuel, the sensor will send a signal to the ECM. If the signal remains constant for 45 seconds, a 97-15 (E232-1) diagnostic code will become active. If the signal remains constant for 1 hour, a 97-16 (E232-2) diagnostic code will become active. These diagnostic codes can also be caused by a short in the WIF sensor circuit.

During the following procedure, refer to the electrical schematic for the application.

Complete the procedure in the order in which the steps are listed.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Turn the keyswitch to the OFF position. B. Thoroughly inspect the connector for the WIF sensor and the P1/J1 ECM connector. Refer to Troubleshooting, "Electrical Connectors - Inspect". C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the WIF sensor. D. Check the screw for the ECM connector for the correct torque of 6 N·m (53 lb in). E. Check the harness for abrasions, for pinch points, and for corrosion.	Loose connection or damaged wire	Result: There is a fault in a connector or the wiring. Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and ensure that the connectors are correctly coupled. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points. Proceed to Test Step 2.
2. Check For Active Diagnostic Codes A. Turn the keyswitch to the OFF position. B. Connect the electronic service tool to the diagnostic connector. C. Turn the keyswitch to the ON position. If the engine will start, then run the engine. D. Wait for at least 1 minute. E. Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes.	Diagnostic codes	Result: There are no active diagnostic codes for the WIF sensor. There may be an intermittent fault. Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" to identify intermittent faults. Result: A 97-15 (E232 (1)) or 97-16 (E232 (2)) diagnostic code is active. Refer to Troubleshooting, "Fuel Contains Water" before continuing with this procedure. Proceed to Test Step 3. Result: A 97-3 (3547-3) diagnostic code is active. Proceed to Test Step 3.
3. Check the Supply Voltage at the Sensor Connector Note: Refer to the Electrical Schematic for the application to determine the sensor supply voltage. A. Turn the keyswitch to the OFF position. B. Disconnect the WIF sensor connector. C. Turn the keyswitch to the ON position. D. Measure the voltage between the sensor supply and sensor return terminals on the harness connector for the WIF sensor. E. Turn the keyswitch to the OFF position.	Between 11 VDC and 13 VDC for a 12 VDC system. Between 22 VDC and 26 VDC for a 24 VDC system. Between 7.5 VDC and 8.5 VDC for an 8 VDC supply	Result: The voltage is not within the expected range. The fault is in the sensor supply wire or the return wire . Repair: Repair the faulty sensor connector or replace the faulty harness. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The voltage is within the expected range. Reconnect the WIF sensor to the harness. Proceed to Test Step 4.
4. Check that the Diagnostic Code is Still Active A. Turn the keyswitch to the OFF position. B. Connect the electronic service tool to the diagnostic connector. C. Turn the keyswitch to the ON position. Wait for at least 1 minute. D. Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes.	Diagnostic code	Result: A 97-3 (3547-3) diagnostic code is active. Proceed to Test Step 5. Result: A 97-15 (E232 (1)) diagnostic code is active. Proceed to Test Step 6. Result: No diagnostic code is active. Return the unit to service.
5. Create a Short Circuit at the Sensor Connector A. Turn the keyswitch to the OFF position. B. Disconnect the WIF sensor from the harness. C. Fabricate a jumper wire that is 150 mm (6 inch) long. D. Use the jumper to connect the sensor signal terminal to the sensor return terminal on the harness connector for the WIF sensor. E. Turn the keyswitch to the ON position. Wait for at least 1 minute. F. Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes.	Open circuit	Result: A 97-3 (3547-3) diagnostic code was active before installing the jumper. A 97-15 (E232 (1)) code was active with the jumper installed. There is an open circuit in the WIF sensor. Repair: Install a replacement sensor. Refer to Disassembly and Assembly, "Water Separator and Fuel Filter (Primary) - Remove and Install" for the correct procedure. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: There is still an active 97-3 (3547-3) diagnostic code with the jumper installed. The sensor is OK. Proceed to Test Step 7.
6. Check the Harness for an Open Circuit A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the water-in-fuel sensor and P1 connector. C. Use a multimeter to check the resistance of the sensor signal wiring between the sensor connector and the P1 connector. Note: Refer to the Electrical Schematic for the application for the correct terminals. D. Install the removed connectors.	Less than 2.0 Ohms.	Result: The measured resistances are greater than 2.0 Ohms. There is an open circuit in the harness. Repair: Repair the sensor connector or replace the harness. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The measured resistance is less than 2.0 Ohms. There may be a short circuit in the harness. Proceed to Test Step 7.
7. Create an Open Circuit at the Sensor Connector A. Turn the keyswitch to the OFF position. B. Disconnect the WIF sensor from the harness. C. Turn the keyswitch to the ON position. Wait for at least 1 minute. D. Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes.	Short circuit	Result: A 97-15 (E232 (1)) diagnostic code remains active with the WIF sensor connected. A 97-3 (3547-3) diagnostic code was active after disconnecting the WIF sensor. There is a short in the WIF sensor. Install a replacement sensor. Refer to Disassembly and Assembly, "Water Separator and Fuel Filter (Primary) - Remove and Install" for the correct procedure. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The 97-15 (3547-3) diagnostic code is still active with the WIF sensor disconnected. The WIF sensor is OK. Proceed to Test Step 8.
8. Check the Harness for a Short Circuit A. Turn the keyswitch to the OFF position. B. Disconnect the WIF sensor from the harness. Disconnect the P1 connector. C. Use a multimeter to measure the resistance between the WIF sensor signal terminal on the P1 connector and all other terminals on P1. D. Reconnect the WIF sensor to the harness. Reconnect the P1 connector.	Greater than 100 Ohms	Result: The measured resistances are less than 100 Ohms. There is a short in the harness. Repair: Repair the faulty sensor connector or replace the faulty harness. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The measured resistance is greater than 100 Ohms. There is a fault in the ECM. Contact the Dealer Solutions Network (DSN).