C7.1 Engines and Generator Sets Caterpillar

ARD Fuel Supply - Test

Usage:

C7.1 770

Use this procedure if the ARD fuel pump is not operating correctly.

Also, use this procedure covers the following codes:

Show/hide table

Table 1
Diagnostic Trouble Codes for the Aftertreatment Regeneration Device (ARD) Fuel Pump Relay
J1939 Code	CDL Code	Code Description (code descriptions may vary)	Comments
5423-5	3427-5	Aftertreatment Regeneration Device Fuel Pump Relay : Current Below Normal	The Electronic Control Module (ECM) detects the following conditions: A low current condition (open circuit) in the circuit for the ARD fuel pump relay for one second. The ECM has been powered for at least one second. The ECM is not attempting to power the ARD fuel pump relay.
5423-6	3427-6	Aftertreatment Regeneration Device Fuel Pump Relay : Current Above Normal	The ECM detects the following conditions: A high current condition (short circuit) in the circuit for the ARD fuel pump relay for at least one second. The ECM has been powered for at least one second. The ECM is attempting to power the ARD fuel pump relay.

Show/hide table




Illustration 1	g06143030
Typical schematic of the circuit for the ARD fuel pump

Show/hide table




Illustration 2	g02159023
Typical example of the connector for the ARD fuel pump (1) Power (2) Return

Show/hide table




Illustration 3	g02006473
View of the pin locations on the P2 connector for the ARD fuel pump relay (41) ARD fuel pump relay return (42) ARD fuel pump relay control

The following background information is related to this procedure:

The ARD increases the exhaust gas temperature to a sufficient level to burn off the soot that is collected in the Diesel Particulate Filter (DPF). The ARD requires a supply of fuel and clean air. The fuel supply is provided by the ARD fuel pump.

When a DPF regeneration is required, the ECM will activate the relay that controls the ARD fuel pump.

Override for the Relay

The electronic service tool includes the "Aftertreatment Fuel Pump Override". This override will assist the analysis of the ARD fuel pump circuit. The override can be used to control the operation of the ARD fuel pump while the engine is not running.

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

Show/hide table

Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Inspect the P2/J2 connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. B. Inspect the 31-pin connector and the ARD fuel pump relay connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. C. Inspect the connector for the ARD fuel pump. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. D. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the aftertreatment identification module. E. Check the screw for the ECM connector for the correct torque of 6 N·m (53 lb in). F. Check the harness for abrasion and pinch points from the aftertreatment identification module back to the ECM.	Connectors and wiring	Result: There is a fault with the harness or the connectors. Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all the seals are correctly in place and ensure that the connectors are correctly connected. Use the electronic service tool to clear all logged diagnostic codes and then verify that the repair has eliminated 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 Diagnostic Codes A. Establish communication between the electronic service tool and the engine ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Turn the keyswitch to the ON position. C. Download the following items before performing any troubleshooting or clearing any diagnostic codes: · Warranty report · Aftertreatment regeneration trigger history · Product status report with histograms D. Start the engine. Make a note of any active diagnostic codes. E. Use the electronic service tool to select the "Aftertreatment Fuel Pump Override" to turn on the power for the ARD fuel pump. Make a note of any active diagnostic codes.	Diagnostic code	Result: Diagnostic code 5423-5 (3427-5) is active when the ARD fuel pump is switched off. Proceed to Test Step 3. Result: Diagnostic code 5423-6 (3427-6) is active when the ARD fuel pump is switched on. Proceed to Test Step 5. Result: An active diagnostic code or a recently logged diagnostic code was not displayed. There may be a fault with the switched power circuit for the ARD fuel pump. The ECM does not monitor the status of this condition. Proceed to Test Step 9.
3. Create a Short Circuit at the ARD Fuel Pump Relay A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the ARD fuel pump relay. C. Fabricate a jumper wire that is 150 mm (6 inch) long. D. Use the jumper wire to connect Test Point 1 to Test point 2 on the harness connector for the ARD fuel pump relay. Refer to Illustration 1. E. Start the engine. Use the electronic service tool to check for an active 5423-5 (3427-5) diagnostic code. F. Use the electronic service tool to select the "Aftertreatment Fuel Pump Override" to activate the ARD fuel pump. Check for an active 5423-6 (3427-6) diagnostic code. G. Stop the engine and remove the jumper.	Short circuit.	Result: A 5423-6 (3427-6) diagnostic code was active with the jumper installed. Repair: Install a replacement relay. Reconnect the connector for the ARD fuel pump relay. Start the engine. Use the electronic service tool to check for an active 5423-5 (3427-5) diagnostic code. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Check for an active 5423-6 (3427-6) diagnostic code. Confirm that the fault has been eliminated. Result: A 5423-5 (3427-5) diagnostic code is still active with the jumper installed. Reconnect the ARD fuel pump relay and proceed to Test Step 4.
4. Create a Short Circuit at the 31-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 31-pin connector. C. Fabricate a jumper wire that is 150 mm (6 inch) long. D. Insert one end of the jumper into socket 19 on the 31-pin connector on the engine harness. Insert the other end of the jumper into socket 26 on the 31-pin connector on the engine harness. E. Start the engine. Use the electronic service tool to check for a 5423-5 (3427-5) diagnostic code. Note: While the 31-pin connector is disconnected, diagnostic codes for the other components that are connected to the 31-pin connector will be active. Disregard the diagnostic codes for all the other components. Only address the 5423 (3427) diagnostic codes. F. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Check for an active 5423-6 (3427-6) diagnostic code. Note: While the 31-pin connector is disconnected, diagnostic codes for the other components that are connected to the 31-pin connector will be active. Disregard the diagnostic codes for all the other components. Only address the 5423 (3427) diagnostic codes. G. Stop the engine and remove the jumper.	Short circuit	Result: A 5423-6 diagnostic code is active with the jumper installed. The fault is in the wiring between the 31-pin connector and the ARD fuel pump relay. Repair: Repair the faulty wiring or replace the faulty wiring. Reconnect the 31-pin connector. Use the electronic service tool to clear all logged diagnostic codes. Start the engine. Use the electronic service tool to check for an active 5423-5 (3427-5) diagnostic code. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Check for an active 5423-6 (3427-6) diagnostic code. Confirm that the fault has been eliminated. Result: A 5423-5 diagnostic code is still active with the jumper installed. Proceed to Test Step 7.
5. Bypass the Engine Harness A. Turn the keyswitch to the OFF position. B. Disconnect the P2 connector. C. Inspect the P2/J2 connector. Refer to Troubleshooting, "Electrical Connectors - Inspect". D. Remove the wires from P2:41 and P2:42. E. Remove the wires from socket 26 and socket 19 on the 31-pin connector on the engine harness. F. Fabricate two jumper wires that are long enough to reach from the ECM to the 31-pin connector. G. Insert one end of a jumper into P2:41. Insert the other end of the jumper into socket 19 on the 31-pin connector on the engine harness. H. Insert one end of the other jumper into P2:42. Insert the other end of the jumper into socket 26 on the 31-pin connector on the engine harness. I. Reconnect the P2 connector and the 31-pin connector J. Start the engine. Use the electronic service tool to check for an active 5423-5 (3427-5) diagnostic code. K. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Check for an active 5423-6 (3427-6) diagnostic code. L. Stop the engine. M. Disconnect the P2/J2 connector and the 31-pin connector. Remove the jumper wire..	Harness bypass	Result: There are no active 5423 (3427) diagnostic codes. The fault is in the engine harness between the ECM and the 31-pin connector. Repair: Repair the faulty wiring or replace the faulty wiring. Reconnect the P2/J2 connector and the 31-pin connector. Start the engine. Use the electronic service tool to check for an active 5423-5 (3427-5) diagnostic code. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Check for an active 5423-6 (3427-6) diagnostic code. Confirm that the fault has been eliminated. Result: A 5423 (3427) diagnostic code is still active. Return all wires to the original configuration and contact the Dealer Solutions Network (DSN).
6. Check the Input Voltage to the Relay A. Disconnect the connector for the ARD fuel pump relay. B. Check the voltage between Test Point A on the harness connector for the ARD fuel pump relay and a suitable ground.	For 12 V systems, 11.0 to 13.5 VDC. For 24 V systems, 22.0 to 27.0 VDC.	Result: The voltage is not within the expected range. The fault is in the wiring between the battery and the ARD fuel pump. Repair: Replace any blown fuses. Repair the faulty wiring or replace the faulty wiring. Start the engine. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Confirm that the fault has been eliminated. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to deactivate the ARD fuel pump. Result: The voltage is within the expected range. The wiring between the battery and the ARD fuel pump relay is OK. Reconnect the connector for the relay and proceed to Test Step 7.
7. Check the Voltage at the Connector for the ARD Fuel Pump A. Disconnect the connector for the ARD fuel pump. B. Start the engine and use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. C. Measure the voltage at terminal 1 of the harness connector for the ARD fuel pump to a suitable ground.	For 12 V systems, 11.0 to 13.5 VDC. For 24 V systems, 22.0 to 27.0 VDC.	Result: The ARD fuel pump is not receiving the correct voltage. Proceed to Test Step 9. Result: The ARD fuel pump is receiving the correct voltage. Proceed to Test Step 8.
8. Check the Return Wire for the ARD Fuel Pump A. Start the engine. B. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. C. Measure the voltage from terminal 1 to terminal 2 of the harness connector for the ARD fuel pump. Stop the engine.	For 12 V systems, 11.0 to 13.5 VDC. For 24 V systems, 22.0 to 27.0 VDC.	Result: Battery voltage is not present. The fault is in the wiring between the ARD fuel pump and the negative terminal on the battery. Repair: Repair the faulty wiring or replace the faulty wiring. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump and confirm that the repair eliminates the fault. Result: Battery voltage is present. The wiring between the ARD fuel pump and the negative terminal on the battery is OK. Repair: Replace the ARD fuel pump. Refer to Disassembly and Assembly, "Fuel Pump (ARD) - Remove and Install". Start the engine and use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Confirm that the fault has been eliminated.
9. Bypass the Relay A. Stop the engine. B. Disconnect the connector for the ARD fuel pump relay. C. Ensure that the connector for the ARD fuel pump is disconnected. D. Fabricate a jumper wire that is 150 mm (6 inch) long. E. Use the jumper wire to connect Test Point (A) to Test point (B) on the harness connector for the ARD fuel pump relay. Refer to Illustration 1. F. Measure the voltage from terminal 1 on the harness connector for the ARD fuel pump to a suitable ground. G. Remove the jumper.	For 12 V systems, 11.0 to 13.5 VDC. For 24 V systems, 22.0 to 27.0 VDC.	Result: The voltage is not within the expected range. The fault is in the wiring between the ARD fuel pump and the ARD fuel pump relay. Repair: Repair the faulty wiring or replace the faulty wiring. Start the engine. Use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump and confirm that the repair eliminates the fault. Result: The voltage is within the expected range. There may be a fault with the relay. Repair: Install a replacement relay. Start the engine and use the "Aftertreatment Fuel Pump Override" in the electronic service tool to activate the ARD fuel pump. Confirm that the fault has been eliminated. If the fault is still present, contact the Dealer Solutions Network (DSN).