C3.4B Engines DEF Line Heater

DEF Line Heater - Test

C3.4B Engines [UENR4499]

C3.4B Engines CAN Data Link - Test

C3.4B Engines DEF Pump - Test

AIR INLET AND EXHAUST SYSTEM

AFTERTREATMENT GP

C3.4B Engines DEF Concentration Is Incorrect

C3.4B Engines DEF Module Does Not Respond

C3.4B Engines DEF Pressure Is High

C3.4B Engines DEF Does Not Purge

C3.4B Engines DEF Pressure Does Not Respond

C3.4B Engines DEF Pressure Is Low

C3.4B Engines DEF Tank Level Is Low

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Table 1
Diagnostic Trouble Codes for the DEF Line Heaters
J1939 Code	Description	Notes
4332-7	Aftertreatment #1 SCR System State : Not Responding Properly	The Electronic Control Module (ECM) detects that the Diesel Exhaust Fluid (DEF) pressure line heater is not effectively heating the DEF. The warning lamp will flash. The engine will be derated. When this diagnostic code is active, check for an associated diagnostic code which could indicate the cause of the DEF temperature not responding.
4354-5	Aftertreatment #1 SCR Catalyst Reagent Line Heater #1 : Current Below Normal	This code indicates there is a fault in the DEF suction and return line heater circuit that is most likely an open circuit. The battery voltage is at least 10 V. The warning lamp will come on. The warning lamp may flash and the engine may be derated.
4354-6	Aftertreatment #1 SCR Catalyst Reagent Line Heater #1 : Current Above Normal	This code indicates there is a fault in the DEF suction and return line heater circuit that is most likely a short circuit. The battery voltage is at least 10 V. The warning lamp will come on.
4355-5	Aftertreatment #1 SCR Catalyst Reagent Line Heater #2 : Current Below Normal	This code indicates there is a fault in the DEF pressure line heater circuit that is most likely an open circuit. The battery voltage is at least 10 V. The warning lamp will come on. The warning lamp may flash and the engine may be derated.
4355-6	Aftertreatment #1 SCR Catalyst Reagent Line Heater #2 : Current Above Normal	This code indicates there is a fault in the DEF pressure line heater circuit that is most likely a short circuit. The battery voltage is at least 10 V. The warning lamp will come on.
5491-3	Aftertreatment #1 DEF Line Heater Relay : Voltage Above Normal	The ECM detects the voltage to the Heater Control Unit (HCU) is high. The battery voltage is at least 10 V. The warning lamp will flash. The engine will be derated.
5491-4	Aftertreatment #1 DEF Line Heater Relay : Voltage Below Normal	The ECM detects the voltage to the HCU is low. The battery voltage is at least 10 V. The warning lamp will flash. The engine will be derated.
5491-6	Aftertreatment #1 DEF Line Heater Relay : Current Above Normal	The ECM detects an over temperature fault from the HCU. The warning lamp will flash. The engine will be derated.
5491-7	Aftertreatment #1 DEF Line Heater Relay : Not Responding Properly	The ECM detects that the HCU is not responding. The battery voltage is at least 10 V. The warning lamp will come on.
5491-19	Aftertreatment #1 DEF Line Heater Relay : Data Error	The ECM has stopped receiving data over the CAN data link from the HCU. The warning lamp will come on.
5706-5	Aftertreatment #1 Diesel Exhaust Fluid Pump Heater : Current Below Normal	This code indicates there is a fault in the DEF pump heater circuit that is most likely an open circuit. The battery voltage is at least 10 V. The warning lamp will come on. The warning lamp may flash and the engine may be derated.
5706-6	Aftertreatment #1 Diesel Exhaust Fluid Pump Heater : Current Above Normal	This code indicates there is a fault in the DEF pump heater circuit that is most likely a short circuit. The battery voltage is at least 10 V. The warning lamp will come on.
Follow the troubleshooting procedure in order to identify the root cause of the fault.

The Heater Control Unit (HCU) supplies battery voltage to the DEF line heaters. If there is a fault on one of the DEF line heaters, the HCU will send a diagnostic message to the engine Electronic Control Module (ECM).

DEF Line Heater Overrides

The electronic service tool can be used to override each of the three outputs from the HCU individually. Navigate to the following menus in order to access the DEF line heater overrides:

Diagnostics
Diagnostic Tests
Override Parameters

There are three DEF line heater overrides available:

DEF Pump Heater Override
DEF Backflow and Suction Line Heater Override
DEF Pressure Line Heater Override

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Illustration 1	g03718797
Schematic diagram of the DEF heater circuit Not all connectors are shown. Refer to the Electrical Schematic for the application.

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Illustration 2	g03718801
View of the pin locations for the DEF line heaters on the J1 connector (23) CAN 2 + (45) CAN 2 -

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Illustration 3	g03718804
View of the pin layout on the HCU (G1) DEF pump heater (G2) DEF suction line and return line heater (G4) DEF pressure line heater (87) Switched battery (+) (31) Battery (-) (DI) CAN 2 (-) (30) Battery (+) (ST) CAN 2 (+)

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Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Check the fuses. B. Inspect the J1/P1 ECM connector. C. Inspect the connectors for the DEF line heaters and the HCU. D. Perform a 30 N (6.7 lb) pull test on each of the wires in the ECM connector, the HCU connector, and the line heaters. E. Check all of the wiring associated with the DEF line heaters for abrasions and pinch points.	Damaged wire or connector	Result: A damaged wire or damaged connector was not found. Proceed to Test Step 2. Result: A damaged wire or damaged connector was found. Repair: Repair the damaged wire or the damaged connector. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
2. Check for Active Diagnostic Codes A. Establish communication between the electronic service tool and the ECM. If necessary, refer to Troubleshooting, "Electronic Service Tools". B. Use the electronic service tool to check for active diagnostic codes.	Diagnostic Trouble Codes	Result: One of the diagnostic codes listed in Table 1 is active. Proceed to Test Step 3. Result: A 1231-9 diagnostic code is active. A fault exists on the CAN data link. Repair: Troubleshoot this diagnostic code before continuing with this procedure. Refer to Troubleshooting, "CAN Data Link - Test". Result: None of the preceding diagnostic codes are active. If one of the preceding diagnostic codes is recently logged, an intermittent fault may exist. Repair: Refer to Troubleshooting, "Electrical Connector - Inspect" in order to identify intermittent faults.
3. Check the Power Supply and Ground for the HCU A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the HCU. C. Turn the keyswitch to the ON position. D. Use a multimeter to measure the voltage between the following points: · Terminal 87 and terminal 31 on the harness connector for the HCU. Terminal 30 and terminal 31 on the harness connector for the HCU. E. Turn the keyswitch to the OFF position.	10 V to 14 V	Result: One of the voltage measurements is not within the expected range. There is a fault in the power supply wiring to the HCU. Repair: Check the fuses. If the fuses are OK, there is an open circuit in the power supply wiring to the HCU. If a fuse is blown, there may be a short circuit in the power supply wiring to the HCU. Result: Both voltage measurements are not within the expected range The fault is most likely in the ground wiring for the HCU. Repair: Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: Both voltage measurements are within the expected range. Proceed to Test Step 4.
4. Check the CAN Data Link for the HCU A. Turn the keyswitch to the OFF position. B. Disconnect the harness connector from the HCU. Disconnect the P1 connector from the ECM. C. Use a multimeter to measure the resistance between the following points: · Terminal DI on the harness connector for the HCU and P1:45. · Terminal ST on the harness connector for the HCU and P1:23.	Less than 5 Ohms	Result: At least one of the resistance measurements is greater than 5 Ohms. Repair: Replace the wiring between the HCU and the P1 connector on the ECM. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: Both resistance measurements are less than 5 Ohms. Repair: Reconnect the HCU harness connector and the P1 ECM connector. Proceed to Test Step 5.
5. Check the Power Supply to the DEF Line Heaters A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the DEF pressure line, the DEF suction line, and the DEF pump module. C. Turn the keyswitch to the ON position. D. Use the electronic service tool to activate the "DEF Pressure Line Heater Override". Use a multimeter to measure the voltage between terminal 1 on the harness connector for the DEF pressure line heater and a suitable ground. E. Use the electronic service tool to deactivate the "DEF Pressure Line Heater Override". F. Disconnect the connector for the DEF suction line heater. G. Use the electronic service tool to activate the "DEF Backflow and Suction Line Heater Override". Use a multimeter to measure the voltage between terminal 1 on the harness connector for the DEF suction line heater and a suitable ground. H. Use the electronic service tool to deactivate the "DEF Backflow and Suction Line Heater Override". I. Disconnect the connector for the DEF pump module. J. Use the electronic service tool to activate the "DEF Pump Heater Override". Use a multimeter to measure the voltage between terminal 11 on the harness connector for the DEF pump module and a suitable ground. K. Use the electronic service tool to deactivate the "DEF Pump Heater Override". L. Turn the keyswitch to the OFF position.	10 V to 14 V	Result: All voltage measurements are within the expected range. Proceed to Test Step 7. Result: At least one of the voltage measurements is not within the expected range. Proceed to Test Step 6.
6. Check the Wiring Between the HCU and the Line Heaters A. Turn the keyswitch to the OFF position. B. Disconnect the HCU from the harness. Disconnect the connector for the DEF pressure line, the DEF suction line, and the DEF pump module. C. Use a suitable multimeter to take the following resistance measurements: · G1 on the HCU harness connector to terminal 11 on the DEF pump module harness connector. · G2 on the HCU harness connector to terminal 1 on the DEF suction line heater harness connector. · G4 on the HCU harness connector to terminal 1 on the DEF pressure line heater harness connector.	less than 5 Ohms	Result: At least one of the resistance measurements is greater than 5 Ohms. Repair: Replace the wiring between the HCU and the DEF line heaters. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: All resistance measurements are less than 5 Ohms. Repair: Install a replacement HCU. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
7. Check the Wiring Between the DEF Suction Line Heater and the DEF Return Line Heater A. Turn the keyswitch to the OFF position. B. Disconnect the DEF suction line heater and the DEF return line heater. C. Use a multimeter to measure the resistance between terminal 2 on the DEF suction line heater harness connector and terminal 1 on the DEF return line heater harness connector.	Less than 5 Ohms	Result: The measured resistance is greater than 5 Ohms. Repair: Replace the wiring between the DEF suction line heater and the DEF return line heater. 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 5 Ohms. Proceed to Test Step 8.
8. Check the DEF Line Heaters A. Turn the keyswitch to the OFF position. B. Disconnect the DEF pressure line heater, the DEF suction line heater, the DEF return line heater, and the DEF pump module. C. Use a multimeter to take the following resistance measurements: · Terminal 1 to terminal 2 on each of the DEF line heaters ·Terminal 11 to terminal 12 on the DEF pump module	Continuity	Result: At least one of the resistance measurements indicates an open circuit. Repair: Replace the line heater that indicates an open circuit. Note: If the suspect heater is the DEF pump heater, the DEF pump module must be replaced. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: All resistance measurements indicate continuity. Leave the line heaters disconnected. Proceed to Test Step 9.
9. Check the Ground Connections for the DEF Line Heaters A. Turn the keyswitch to the OFF position. B. Use a multimeter to take the following resistance measurements: · Terminal 2 on the DEF pressure line heater harness connector to a suitable ground · Terminal 2 on the DEF return line heater harness connector to a suitable ground Terminal 12 on the DEF pump module harness connector to a suitable ground	Less than 5 Ohms	Result: At least one of the resistance measurements is greater than 5 Ohms One of the DEF heaters is not grounded correctly. Repair: Check the ground connections for the DEF heaters. If necessary, replace the ground wiring for the DEF heaters. Result: All resistance measurements are less than 5 Ohms. Contact the Dealer Solution Network (DSN).