87118-ZW5-000 Honda MARK, FUSE (90A) (Honda Code 5893201).

Table 1
Diagnostic Trouble Codes for the DEF Pump
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
4374-3 3118-3 Aftertreatment #1 Diesel Exhaust Fluid Pump Motor Speed : Voltage Above Normal This code indicates high voltage to the DEF pump speed sensor.
The code is logged.
4374-4 3118-4 Aftertreatment #1 Diesel Exhaust Fluid Pump Motor Speed : Voltage Below Normal This code indicates low voltage to the DEF pump speed sensor.
The code is logged.
4374-5 3118-5 Aftertreatment #1 Diesel Exhaust Fluid Pump Motor Speed : Current Below Normal This code indicates low current to the DEF pump speed sensor.
The code is logged.
4374-6 3118-6 Aftertreatment #1 Diesel Exhaust Fluid Pump 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 372-5260 Test Kit 1
Illustration 1 g06208444
Schematic diagram for the DEF pump motor
Illustration 2 g06208478
View of the pin locations for the DEF pump on the ECM P1 connector
(5) DEF pump PWM supply
(31) DEF pump signal
(47) DEF pump PWM return
Illustration 3 g03811015
Pin location on the DEF pump connector
(8) PWM return
(9) PWM supply
(10) PWM signalComplete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. 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 diagnostic code that is listed in Table 1.
Proceed to Test Step 2.
2. Inspect Electrical Connectors and Wiring
A. Inspect the ECM P1 connector.
B. Inspect the connector for the DEF pump.
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM P1 connector and the connector for the DEF pump.
D. Check all the wiring associated with the DEF pump for abrasions and pinch points.
Damaged wire or connector
Result: A damaged wire or damaged connector was not found.
Proceed to Test Step 3.
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.
3. Check for an Open Circuit in the Wiring Harness for the DEF Pump Motor Circuit
A. Turn the keyswitch to the OFF position for 2 minutes to allow the DEF pump to purge, reset the code, and reset the ECM.
B. Disconnect the wiring harness from the DEF pump and the ECM P1 connector.
C. Connect the Tooling A to the DEF pump connector.
Note: Tooling A must be used to prevent damage to the pump connector.
D. Measure the resistance between terminal 9 (PWM +) on the DEF pump connector and P1:5.
E. Measure the resistance between terminal 8 (PWM -) on the DEF pump connector and P1:47.
F. Measure the resistance between terminal 10 (PWM SIGNAL) on the DEF pump connector and P1:31.
Less than 5.0 Ohms
Result: All resistance measurements are less than 5.0 Ohms.
Proceed to Test Step 4.
Result: At least one of the resistance measurements is greater than 5.0 Ohms.
Repair: There is an open circuit in the harness. Repair the wiring or replace the harness.
Proceed to Test Step 6.
4. Check for Short Circuits in the Wiring Harness for the DEF Pump Motor Circuit
A. Turn the keyswitch to the OFF position. The keyswitch must be OFF for 2 minutes to allow the DEF pump to purge, reset the code, and reset the ECM.
B. Disconnect the wiring harness from the DEF pump and the ECM P1 connector.
C. Connect Tooling A to the DEF pump connector.
Note: Tooling A must be used to prevent damage to the pump connector.
D. Measure the resistance between terminal 9 (PWM +) on the DEF pump connector and a known good chassis ground.
E. Measure the resistance between terminal 8 (PWM -) on the DEF pump connector and a known good chassis ground.
F. Measure the resistance between terminal 10 (PWM SIGNAL) on the DEF pump connector and a known good chassis ground.
Greater than 100k Ohms
Result: All resistance measurements are greater than 100k Ohms.
Proceed to Test Step 5.
Result: At least one of the resistance measurements is less than 100k Ohms.
Repair: There is a short circuit in the harness. Repair the wiring or replace the harness.
Proceed to Test Step 6.
6. Perform a DEF Dosing System Verification Test
A. Turn the keyswitch to the "ON" position. Do not start the engine.
B. Connect to the ECM.
C. Perform the "DEF Dosing System Verification Test" .
Diagnostic codes
Result: The code did not return.
Return the unit to service.