C175-16 Locomotive Engine Caterpillar

Use this procedure to troubleshoot a problem with the Diesel Exhaust Fluid (DEF) pump motor. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.

Table 1

J1939 Code and Description	CDL Code and Description	Comments
7107-5 Aftertreatment #1 DEF Pump : Current Below Normal	3118-5 Aftertreatment #1 DEF Pump Motor Speed Sensor : Current Below Normal	There is an open circuit in the DEF pump feedback wiring.
7107-6 Aftertreatment #1 DEF Pump : Current Above Normal	3118-6 Aftertreatment #1 DEF Pump Motor Speed Sensor : Current Above Normal	There is a short circuit in the DEF pump feedback wiring.
7107-11 Aftertreatment #1 DEF Pump : Other Failure Mode	3118-11 Aftertreatment #1 DEF Pump Motor Speed Sensor : Other Failure Mode	A failed DEF Pump has been detected.

Illustration 1	g03741437

Table 2

Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Connect Cat® Electronic Technician (ET) to the service tool connector. B. Determine if a code is active or logged.	Codes	Result: A -5 code is active or logged. Proceed to Test Step 2. Result: A -6 code is active or logged. Proceed to Test Step 3. Result: A -11 code is active or logged. Proceed to Test Step 5.
2. Check the Wiring to the DEF Pump for an Open Circuit A. Remove electrical power from the engine. B. Disconnect the J1 and J2 connector from the SCR controller. C. Disconnect the 3-pin DEF pump harness. D. Measure the resistance between the following pins: - Pin 1 and Pin 18 SCR controller J1 connector - Pin 2 and Pin 44 SCR controller J1 connector - Pin 3 and Pin 45 SCR controller J1 connector	Open Circuit	Result: There were less than 10 ohms of resistance between all of the pins. Proceed to Test Step 6. Result: There were more than 10 ohms of resistance between two or all of the pins. Repair: An open circuit has been detected. Repair or replace the wiring harness. Proceed to Test Step 6.
3. Check the Wiring to the DEF Pump for a Short Circuit to Ground A. Remove electrical power from the engine. B. Disconnect the J1 and J2 connector from the SCR controller. C. Disconnect the 3-pin DEF pump harness. D. Measure the resistance between the following pins: - Pin 1 and Engine ground - Pin 2 and Engine ground - Pin 3 and Engine ground	Short Circuit	Result: There were more than 10 K ohms of resistance between the pins and a known good ground. Proceed to Test Step 4. Result: There were less than 10 K ohms of resistance between the pins and a known good ground. Repair: A short circuit to ground has been detected. Repair or replace the wiring harness. Proceed to Test Step 6.
4. Check the Wiring to the DEF Pump for a Short Circuit A. Remove electrical power from the engine. B. Disconnect the J1 and J2 connector from the SCR controller. C. Disconnect the 3-pin DEF pump harness. D. Measure the resistance between the following pins: - Pin 1 on the DEF pump harness connector and all other pins on the SCR controller J1 connector. - Pin 2 on the DEF pump harness connector and all other pins on the SCR controller J1 connector. - Pin 3 on the DEF pump harness connector and all other pins on the SCR controller J1 connector.	Short Circuit	Result: There were more than 10 K ohms of resistance between each pin and all other pins on the SCR controller J1 connector. Proceed to Test Step 5. Result: There were less than 10 K ohms of resistance between each pin and all other pins on the SCR controller J1 connector. Repair: A wire to wire short has been detected. Repair or replace the wiring harness. Proceed to Test Step 6.
5. Replace the DEF Pump A. Remove electrical power from the engine. B. Replace the DEF Pump.	DEF Pump Replaced	Result: The DEF pump was replaced. Proceed to Test Step 6.
6. Operate the Engine A.Remove electrical power from the engine position for at least 1 minute. B. Apply electrical power to the engine. C. Start the engine. D. Run the engine until normal operating temperature is reached. E. Connect Cat ET. F. Use Cat ET to monitor the following: - "Aftertreatment System State" G. Check for codes when the "Aftertreatment System State" reads "Normal Dosing".	Codes	Result: A code is not active. Return to service. Result: A code becomes active while running the engine. Repair: Troubleshoot the code that came active while running the engine. Verify that the repair eliminated the problem.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).