90029-ZY3-000 Honda BOLT-WASHER (5X18) (Honda Code 6993596).

Table 1
Diagnostic Trouble Codes for the DEF Pump Motor
J1939 Code Code Description Comments
4374-3 Aftertreatment #1 DEF Pump #1 Motor Speed : Voltage Above Normal This code indicates that the voltage is above the acceptable range.
The code is logged.
4374-4 Aftertreatment #1 DEF Pump #1 Motor Speed : Voltage Below Normal This code indicates that the voltage is below the acceptable range.
The code is logged.
4374-5 Aftertreatment #1 DEF Pump #1 Motor Speed : Current Below Normal This code indicates low current to the DEF pump speed sensor.
The code is logged.
4374-6 Aftertreatment #1 DEF Pump #1 Motor Speed : Current Above Normal This code indicates high current to the DEF pump speed sensor.
The code is logged.
Follow the troubleshooting procedure to identify the root cause of the problem.
Table 2
Required Tools
Tool Part Number Part Description Qty
A T4000242 Break-out Connector 1
Illustration 1 g06329112
Schematic diagram for the DEF pump motor
Note: All connectors may not be shown. Refer to the Electrical Schematic for the application for details of any connectors between the DEF pump connector and the ECM connectors.
Illustration 2 g03811015
Pin location on the DEF pump connector
(8) Return
(9) 12V supply
(10) PWM signalComplete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Inspect the connector for the DEF pump.
B. Thoroughly inspect any connectors between the DEF pump and the ECM. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the DEF pump connector and any connectors between the DEF pump and the ECM.
D. Check all the wiring associated with the DEF pump for abrasions and pinch points.
Note: Do not disconnect the ECM connector at this stage. The ECM can only be disconnected and reconnected 10 times before damage to the harness connector may occur.
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. Verify that the repair eliminates the fault.
2. Check that the DEF Pump is Grounded Correctly
A. Turn the keyswitch to the OFF position.
B. Disconnect the harness connector from the DEF pump.
C. Measure the resistance between terminal 8 on the harness connector for the DEF pump and a suitable ground.
Less than 2 Ohms
Result: The resistance is not within the expected range. The fault is in the wiring between the DEF pump connector and battery (-).
Repair: Repair the faulty wiring or replace the faulty wiring.
Result: The resistance is within the expected range.
Proceed to Test Step 3.
3. Determine the Diagnostic Code
A. Establish communication between the electronic service tool and the engine Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools"
B. Look for active or logged codes.
Diagnostic Trouble Codes
Result: There is an active or logged 4374-4 or 4374-5 diagnostic code.
Proceed to Test Step 4.
There is an active or logged 4374-3 or 4374-6 diagnostic code.
Proceed to Test Step 7.
4. Create a Short Circuit at the DEF Pump Harness Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the DEF pump harness connector.
C. Fabricate a jumper wire that is 150 mm (6 inch) long.
D. Install the wire between terminal 9 and terminal 10 on the DEF pump connector to create a short circuit.
E. Turn the keyswitch to the ON position. Use the electronic service tool to start the "DEF Dosing System Verification Test". This test will command the DEF pump on.
F. Check for active diagnostic codes.
G. Use the electronic service tool to stop the "DEF Dosing System Verification Test". Remove the jumper wire from the DEF pump connector.
Short Circuit
Result: A -5 diagnostic code was active before installing the jumper. A -6 diagnostic code is active when the jumper is installed - There is a fault in the DEF pump.
Repair: Install a replacement DEF pump.
Result: A -3 diagnostic code was active before installing the jumper. A -4 diagnostic code is active when the jumper is installed - There is a fault in the DEF pump.
Repair: Install a replacement DEF pump.
Use the electronic service tool to perform the "DEF Dosing System Verification Test" to check that the repair eliminates the fault.
Result: The original diagnostic code is still active with the jumper installed.
Remove the jumper. Reconnect all connectors. Proceed to Test Step 5.
5. Check the Wiring Between the DEF Pump Connector and the Interface Connector (if equipped) for an Open Circuit
Note: This step is only applicable if an interface connector is installed between the DEF pump and the ECM. Refer to the Electrical Schematic for the application for more information. Proceed to Test Step 6 if no interface connector is installed.
A. Turn the keyswitch to the OFF position.
B. Disconnect the DEF Pump connector. Disconnect the interface connector between the DEF pump and the ECM.
C. Use a suitable multimeter to measure the resistance between terminal 10 on the DEF pump harness connector and the appropriate pin/terminal on the interface connector.
D. Use a suitable multimeter to measure the resistance between terminal 9 on the DEF pump harness connector and the appropriate pin/terminal on the interface connector.
Less than 2 Ohms
Result: The resistance is greater than 2 Ohms - There is a fault in the wiring between the DEF pump connector and the interface connector.
Repair: Repair the faulty wiring or replace the faulty wiring.
Use the electronic service tool to perfor